Bump vs Full Length Sizing

[Guest]

ShifuXPrivate
Rating: 0.0/5 this site
34 posts this site
Bump vs Full Length Sizing
03/03/2015

---

I understand the concepts. But can any FL die be used to bump?

Rate now:
reloader112XFirst Sergeant
Rating: 3.0/5 this site
1395 posts this site
Re: Bump vs Full Length Sizing
03/03/2015
(1 vote)

---

If you use a FL die to bump, you will also full length size the case. Just bumping the shoulders is over sold, just FL size and bump the shoulders back.

Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/03/2015
(2 votes)

---

No standard FL die on the market can bump the shoulder without first reducing it's diameter. Even Redding's body dies reduce the diameter of the shoulder and base. If you only wanna bump the shoulde you need to have a custom die made using your fireformed cases.
Rate now:
HodgdonExtreme

XFirst Sergeant
Rating: 3.7/5 this site
2605 posts this site
Re: Bump vs Full Length Sizing
03/03/2015 Last edited 03/03/2015 by HodgdonExtreme

---

spawnof918v wrote: No standard FL die on the market can bump the shoulder without first reducing it's diameter. Even Redding's body dies reduce the diameter of the shoulder and base. If you only wanna bump the shoulde you need to have a custom die made using your fireformed cases.​

Forster makes what they call a "bushing bump" die, which only sizes the neck via bushing, and pushes the shoulder back. No body sizing performed.

Good kit, for certain purposes.

http://www.forsterproducts.com/store.asp?pid=36223
Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/03/2015

---

It still sizes the shoulder.
Rate now:
HodgdonExtreme

XFirst Sergeant
Rating: 3.7/5 this site
2605 posts this site
Re: Bump vs Full Length Sizing
03/03/2015

---

spawnof918v wrote: It still sizes the shoulder.​

Yes, that's the point - it pushes the shoulder back, and sizes the neck per whichever bushing you choose.

It does not size the body.
Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/03/2015
(1 vote)

---

What is the shoulder diameter before and after the bumping operation?
Rate now:
HodgdonExtreme

XFirst Sergeant
Rating: 3.7/5 this site
2605 posts this site
Re: Bump vs Full Length Sizing
03/03/2015
(1 vote)

---

spawnof918v wrote: What is the shoulder diameter before and after the bumping operation?​

First, understand that few of us have the tools/instruments required to truly measure the diameter of the case body where it intersects the shoulder. You can get close with a caliper, and shimmy the caliper up the body until it's just about to pop off the body, but it is not a highly accurate/scientific way to get the measurement.

That said, I did my best and measured several cases fired in my CBI-barreled Savage 308 at .453 plus a cunthair or two. So maybe ~.4532ish, perhaps, though again I caution attempting to quote such exact numbers for such an inexact measuring method.

Anyway, after using my Forster bushing/bump die to achieve .001" bump (having been zeroed on the fired cases), I could detect zero difference in the body/shoulder junction diameter; they still measured ~.453 + a cunthair or so.

I do not stand corrected.
Rate now:
ShifuXPrivate
Rating: 0.0/5 this site
34 posts this site
Re: Bump vs Full Length Sizing
03/03/2015 Last edited 03/03/2015 by Shifu

---

reloader112 wrote:
If you use a FL die to bump, you will also full length size the case. Just bumping the shoulders is over sold, just FL size and bump the shoulders back.​

So when people talk about bumping the shoulders, they usually mean using a FL die to bump the shoulders back (and resize)? It seems no one mentions about using custom dies in the tutorials or youtube videos.

For using an FL to size and bump, does that mean adjusting the die so that it pushes the shoulder back 0.001 to 0.002" from a fireformed case? This will in fact resize the rest case as well?

I saw the forster bump neck sizing die, which can bump. But it seem that if you use it in bump mode (with no bushing), it is really like a FL die?



Rate now:
HodgdonExtreme

XFirst Sergeant
Rating: 3.7/5 this site
2605 posts this site
Re: Bump vs Full Length Sizing
03/03/2015 Last edited 03/03/2015 by HodgdonExtreme
(2 votes)

---

Yes, you've got the idea.

If you "bump" using an FLS die, you will be pinching down the body of the case a little. How much depends on the die you choose - ranging from ~zero with the aforementioned Forster bump die, to ~quite a bit using a small base die. A FLS die will be a little more than zero, and a "National Match" die will usually be a little more yet, but not as much as the smallbase. It'll also vary a little from one brand die to the next - and probably how early on in the die-reamers lifecycle it was used to cut the die.

All that said, I wouldn't overthink this.

Using a FLS die to bump shoulders back ~.001-.002" is what probably 95% of the shooters here do with great success.

There are probably reasons why uber-anal F class shooters and benchresters do things their own different way, but for a practical field rifle, the FLS die is the way to go.

If there is extra accuracy to be had by not sizing the body at ALL, it sure ain't much.
Rate now:
ShifuXPrivate
Rating: 0.0/5 this site
34 posts this site
Re: Bump vs Full Length Sizing
03/04/2015

---

Thanks HodgdonExtreme and everyone else.

This makes sense now. Since I'm starting reloading, I'll definitely use the FLS die and may consider playing with the Forster bump die.

How do you find out small base or measurements of dies? I haven't seen any specs or measurements of dies.

Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/04/2015
(1 vote)

---

Small base dies size the base .001" more than standard dies.
Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/04/2015
(3 votes)

---

---------------------------------------------
--- HodgdonExtreme wrote:

spawnof918v wrote: What is the shoulder diameter before and after the bumping operation?​

First, understand that few of us have the tools/instruments required to truly measure the diameter of the case body where it intersects the shoulder. You can get close with a caliper, and shimmy the caliper up the body until it's just about to pop off the body, but it is not a highly accurate/scientific way to get the measurement.

That said, I did my best and measured several cases fired in my CBI-barreled Savage 308 at .453 plus a cunthair or two. So maybe ~.4532ish, perhaps, though again I caution attempting to quote such exact numbers for such an inexact measuring method.

Anyway, after using my Forster bushing/bump die to achieve .001" bump (having been zeroed on the fired cases), I could detect zero difference in the body/shoulder junction diameter; they still measured ~.453 + a cunthair or so.

I do not stand corrected.

---------------------------------------------

What happens when you bump more than .001"? Does the shoulder diameter increase?

What I'm getting at is that you can't push on one side of the case without affecting the other. You can't bump the shoulder without bowing the case walls. How do you deal with springback? Some cases spring back more than others? Some cases require more shoulder bump than others. How do you deal with all that?

By that definition a Lee collet neck die bumps the shoulder .001" as well.
Rate now:
tucker301

XModerator
Rating: 3.3/5 this site
9950 posts this site
Re: Bump vs Full Length Sizing
03/04/2015 Last edited 03/04/2015 by tucker301

---

I've been trying to understand bump sizing for a couple of weeks now, and what was just said is what I have not been able to resolve either.

If you move .001 here, it has to go somewhere.

That and I have no idea how to set a FL die to only engage the shoulder and leave the rest of the case alone.



Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/04/2015
(1 vote)

---

You can't.

The only way to do this is to get a custom die made using specs off your fireformed cases. The wsy a FL die works is the body and shoulder get reduced in diameter first and this pops the shoulder forward. As the die finishes sizing the neck it finally contacts the shoulder and bumps it back which swages some of it into the neck. And so the case grows in length.
Rate now:

 

[Guest]

drjjlXSergeant
Rating: 3.1/5 this site
172 posts this site
Re: Bump vs Full Length Sizing
03/06/2015
(1 vote)

---

---------------------------------------------
--- spawnof918v wrote:

You can't.

The only way to do this is to get a custom die made using specs off your fireformed cases. The wsy a FL die works is the body and shoulder get reduced in diameter first and this pops the shoulder forward. As the die finishes sizing the neck it finally contacts the shoulder and bumps it back which swages some of it into the neck. And so the case grows in length.

---------------------------------------------

This. When I was first learning (still learning) and setting up my FL dies, I noticed that at first my base to shoulder measurement actually got LONGER...screwed the die in little by little until the shoulder finally got bumped back .002 from fired brass measurement. The brass gets squeezed and pushed and has to go somewhere.
Rate now:
goodgorillaXSergeant
Rating: 3.1/5 this site
488 posts this site
Re: Bump vs Full Length Sizing
03/08/2015 Last edited 03/08/2015 by goodgorilla

---

How far back should I keep the shoulder? Should I bump it back .002 from a once fired case or bump it back to virgin brass length?

Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
03/08/2015
(1 vote)

---

.002" for bolt gun, .004" for semiautos.
Rate now:
ZenBiker990

X64 MONTHS
Premium Member
Sergeant
Rating: 3.2/5 this site
319 posts this site
Re: Bump vs Full Length Sizing
03/11/2015
(2 votes)

---

I've done both. For me, neck sizing was more of a problem than a solution, especially if the chamber is not perfect and you don't index your cartridges. My recommendation is to buy the best full length sizing dies you can buy. i.e. Redding; use bushing dies if you want to go that route ( I personally don't ), then buy a headspace gauge so you can set your sizing die to bump the shoulder back between 0.001-0.002". I've used several brands and configurations of gauges, but I just got the one designed by Larry Willis/innovative Technologies (larrywillis.com) and have found it to be the best, easiest to use, and most accurate. For $100 it handles any cartridge and uses a digital readout gauge; beats the hell out of squinting at those tiny numbers on dial indicators. FWIW, I recommend FL sizing with minimum shoulder "bump" over neck sizing.
Rate now:
HHarkeX376 MONTHS
Premium Member
Sergeant
Rating: 3.0/5 this site
410 posts this site
Re: Bump vs Full Length Sizing
03/19/2015

---

You can have a custom honed FL bushing die made from a Redding Body die and 5-10 fired cases for $80

Jim Carstenson at JLC Precision will take a Redding Body die and 10 cases fired 3x and hone the body die to perfectly FL size your brass AND convert it to bushings with a deprimer that does not use an expander ball

One of the best deals you can find to increase your accuracy. Just google JLC precision. Take about 2-3 weeks normally
Rate now:
OpxnvXCorporal
Rating: 3.2/5 this site
96 posts this site
Re: Bump vs Full Length Sizing
03/29/2015 Last edited 03/29/2015 by Opxnv

---

That sounds like a pretty good deal. How much did you see on the target?

I use a Redding FL with bushings to control neck tension. I set the die up so that the bolt handle (sans firing pin group and ejector pin) drops roughly halfway (or 2/3 of the way) then I can close it the rest of the way with 1 finger. Even if the gun gets dirty I can still close the bolt. I have good chambers so the alignment is right.

For one of my guns a custom fit die would be good. The 308s were mostly cut with different reamers so, for me, there isn't much point.
Rate now:
6mmcreedmoorXFirst Sergeant
Rating: 3.1/5 this site
3057 posts this site
Re: Bump vs Full Length Sizing
04/12/2015

---

HodgdonExtreme wrote:

spawnof918v wrote: No standard FL die on the market can bump the shoulder without first reducing it's diameter. Even Redding's body dies reduce the diameter of the shoulder and base. If you only wanna bump the shoulde you need to have a custom die made using your fireformed cases.​

Forster makes what they call a "bushing bump" die, which only sizes the neck via bushing, and pushes the shoulder back. No body sizing performed.

Good kit, for certain purposes.

http://www.forsterproducts.com/store.asp?pid=36223​

My Hornady 6 Creed custom NS only bushing die bumps the shoulder, have another which sizes the body and bumps the shoulder.​

Rate now:
spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
04/18/2015
(2 votes)

---

Whenever you bump the shoulder, the body expands. The die has to size the body to some extent, otherwise the round won't chamber.
Rate now:
SHahhshootXGunny Sergeant
Rating: 3.3/5 this site
853 posts this site
Re: Bump vs Full Length Sizing
04/20/2015
(2 votes)

---

HodgdonExtreme wrote:​

That said, I did my best and measured several cases fired in my CBI-barreled Savage 308 at .453 plus a cunthair or two.​

Was this a standard cunthair or a red cunthair? As I'm sure you well-know, the red cunthair is the finest unit of measurement within the industry at this time. Just wanted to clarify for those who may have a RCH indicator and not the ICH.

Rate now:
mkollman74XFirst Sergeant
Rating: 3.8/5 this site
1518 posts this site
Re: Bump vs Full Length Sizing
04/30/2015
(2 votes)

---

Just FL size and be done. I FL size all of my brass everytime I load. Doesn't seem to affect accuracy a bit in my 6 Creed or .308. of course, I am the laziest reloader around. I do as little as possible to get the accuracy I need. I've found much of the brass prep voodoo isn't required at all. YMMV.
Rate now:
ThebellyXGunny Sergeant
Rating: 3.2/5 this site
632 posts this site
Re: Bump vs Full Length Sizing
05/04/2015

---

mkollman74 wrote: Just FL size and be done. I FL size all of my brass everytime I load. Doesn't seem to affect accuracy a bit in my 6 Creed or .308. of course, I am the laziest reloader around. I do as little as possible to get the accuracy I need. I've found much of the brass prep voodoo isn't required at all. YMMV.​

I recently had a struggle with FL vs. Bump only sizing of the brass body. To make a long story short: I tried to get fancy with it, and I ended up with a lot of frustration over the whole thing.

If you plan on using your rifle in a field-like environment, just set up your FL sizing die to bump the shoulders back and be done with it.
Rate now:
A1J04

XFirst Sergeant
Rating: 3.0/5 this site
5624 posts this site
Re: Bump vs Full Length Sizing
05/13/2015 Last edited 05/14/2015 by A1J04
(1 vote)

---

This has been entertaining as hell. lmao. We've all been there and over thought this, for ions. We're some crazy little monkeys who just like to make stuff hard on ourselves.

Ya, just slam the Full Length Sizing Die in the press, screw it down till it makes contact with shell holder and then back it off a few turns. Place a "FIRE FORMED" case with it's neck and shoulder either blackened with a sharpy or smoke it with a candle into the shell holder, run it all the way up and see if the markings are say around half way down the neck. Turn it down a tad more and do it again till you've sized the neck and touched/bumped the shoulder back .002 bolt/.004 other. You'll drive yourself crazy if you try to figure too much of this out at one time, especially when you think you're making your case shorter but it's GROWING ha.

Too much fun.

Rate now:
ZmechanicXPrivate
Rating: 3.1/5 this site
42 posts this site
Re: Bump vs Full Length Sizing
05/29/2015

---

I went through the same thing. Before I bought a headspace comparator for my rounds, I set the sizing by using the stripped bolt and chambering the brass and checking the "fit" in the chamber. I don't advise this, it nearly drove me insane.

I will say, if you run your brass through a FL sizer, but don't let it also touch the shoulder, the headspace will most likely INCREASE. This has been my experience, anyway. Thinking about it, it makes sense. If the FL sizer shrinks the body of case any, where is that going to go? It's going to make it longer. I have had more than one person tell me to just "back the FL sizer out" if I don't want to bump the shoulder. After experiencing the headspace increasing, I quickly disregarded that "advice". I also don't like FL sizing without bottoming out the die on the shellplate. My rationale is that if you don't, then the shoulder bump amount becomes dependant on press rigidity and brass hardness. That would be a YMMV kind of thing, and I know I probably have one of the least rigid press setups around. In any case, I prefer to eliminate as many variables as possible. I would advise that if you want to control the headspace with a FL sizer, adjustable shell plates are the way to go.

I've also heard people say to take the de-capper/expander out of their FL sizer. I've never seen how that would be a benefit, at least with the FL sizers I've seen. Most of them shrink the neck a decent amount under what it needs to be, then rely on the expander to, well, expand it back out. If you take that out, your neck tension would be ludicrous. The option there is a bushing die, or a custom honed FL sizer.

Also, don't always believe the equipment. I had a LEE shell plate that was almost 0.002" too shallow. If I let the die bottom out on it, it would actually produce cases that were below the min headspace on my case gauge. Not cool.
Rate now:
bigedp51XGunny Sergeant
Rating: 2.9/5 this site
768 posts this site
Re: Bump vs Full Length Sizing
06/24/2015 Last edited 10/28/2015 by bigedp51

---

Shifu wrote:
I understand the concepts. But can any FL die be used to bump?​

We live in a plus and minus manufacturing world and no two dies and chambers are exactly the same. I have a Lee .223 full length resizing die that pushes the shoulder back .009 shorter than a GO gauge and .011 shorter than the chamber headspace. It also sizes the base of the case smaller in diameter than two small base dies I have.



In the illustration below is the exaggerated effects of full length resizing, pay close attention to the blue, red and green dotted lines and the word shoulder setback

 

[Guest]

The more you push the shoulder back from its fired length the "MORE" head clearance you create with your reloaded cartridge. And the more room you give the case to thin and stretch in the base web area when fired, which causes case head separations.

If you have too much head clearance when fired the brass will exceed its elastic limits and stretch and thin in the base web area.

Below is a fired unresized .223/5.65 case in my Hornady cartridge case headspace gauge.

Below the same case after full length resizing with .003 shoulder bump. (shoulder setback)

Below on the left is the Redding competition shell holder used on the case above, this shell holder where the base of the case rests is .004 "LOWER" than the standard RCBS shell holder on the right. And with the Redding shell holder the press still reaches cam over, and if the RCBS shell holder on the right had been used with the press reaching cam over, the shoulder of the case would have been pushed back .007.

Bottom line, your dies are threaded and can move up and down and can be adjusted for the correct amount of shoulder setback for "YOUR" rifle.

Rate now:
dondlhmn

XGunny Sergeant
Rating: 3.0/5 this site
631 posts this site
Re: Bump vs Full Length Sizing
07/02/2015 Last edited 07/03/2015 by dondlhmn

---

This is an interesting discussion. I have a couple of 6.5 Creedmoor rifles that have different dimensioned (but only BARELY) chambers.. Rifle" A" has a sort of "tight"chamber. Cases fired in that rifle don't get expanded as much s the cases in rifle "B", which has a slightly (but still within correct tolerances) larger chamber. Brass fired in Rifle "B" will not go into the chamber of rifle "A" and allow the bolt to be closed on it without a good bit of grunting, but a piece of brass fired in rifle "A" will go into the chamber on "B" with no problems at all. Even now part of my cure for all this is to keep the brass used in these two rifles, even though it is the same brand and caliber and number of firings, separate, which is no big deal since I tend to keep brass separate for each rifle I have, anyway. The rifle with the tighter chamber will, after the brass has been neck sized only for several firings, it will (as is pretty normal behavior for baras) expand to the point where it will be difficult to get the bolt to close. I tend to check neck lengths (and brass trim length) pretty carefully after neck sizing and trim as necessary. BUT, what happens is that the case gets harder and harder to chamber and then impossible.....I thought that the case was growing in length might have something to do with this problem (maybe a little too much headspace?), resulting in the shoulder being too far forward and giving me the hard bolt closing. So, I tried running those cases through a FL sizing die (actually tried THREE DIFFERENT BRANDS of DIES). After doing that the brass was still a hard fit...bolt closing was tough....so I started doing some checking of case dimensions in all directions and discovered that even though the case was FL sized, the area about .200" ahead of the ejector groove and just ahead of the "web" was showing signs of interference (I used Dykem on the brass to show where it was making contact) so, after FL resizing and finding that the cases were still tight in the chamber, I stuck one in a collet chuck in my lathe and started shaving a couple of TEN THOUSANDS of an inch at a time off of the part of the case showing the contact and then trying it in the chamber. After shaving off a little a couple of times and still not having the bolt want to close, I suddenly found that the bolt closed and the brass showed no signs of interference, hard contact or anything else. Along the way I thought that maybe I was having a pressure problem, but the cases showed no signs of stretch or getting thin anywhere....SO...I got hold of a small base resizing die and ran the cases for rifle "A" through that about every 3rd or 4th loading and just neck sized the rest of the time. Problem solved....it turns out that the chamber in rifle "a" is a few ten thousandths (like 3 or 4) tighter than the usual spec for that cartridge so Fl resizing just wasn't taking them down far enough by about 3 or 4 TEN thousandths. So now I NEVER SB resize for Rifle "B" and only do an occasional FL sizing while doing only the neck sizing most of the time, but occasionally SB the brass for Rifle "A". Both brass life and accuracy remain great with both rifles and I think I am doing the right thing.....!?!?!?!?

Rate now:

 

[Guest]

spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
07/18/2015
(1 vote)

---

SB resizing does not affect accuracy or case life. I SBFL size for everything, taking care to bump the shoulder minimally. I am fortunate my semi-auto chamber is within .001" of my bolt gun chamber in terms of headspace. But a FC case sized that way will last in excess of 20 firings with moderate (50KPSI) loads.
Rate now:
ZenBiker990

X64 MONTHS
Premium Member
Sergeant
Rating: 3.2/5 this site
319 posts this site
Re: Bump vs Full Length Sizing
08/12/2015
(3 votes)

---

A1J04 wrote:

This has been entertaining as hell. lmao. We've all been there and over thought this, for ions. We're some crazy little monkeys who just like to make stuff hard on ourselves.

Ya, just slam the Full Length Sizing Die in the press, screw it down till it makes contact with shell holder and then back it off a few turns. Place a "FIRE FORMED" case with it's neck and shoulder either blackened with a sharpy or smoke it with a candle into the shell holder, run it all the way up and see if the markings are say around half way down the neck. Turn it down a tad more and do it again till you've sized the neck and touched/bumped the shoulder back .002 bolt/.004 other. You'll drive yourself crazy if you try to figure too much of this out at one time, especially when you think you're making your case shorter but it's GROWING ha.

Too much fun.​

The force is strong with this one. Wise, he is.

Rate now:
SH10FPXPrivate
Rating: 0.0/5 this site
2 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

I am relatively new to reloading but not a full novice. This thread is interesting to me as I had problems with resizing for my Savage 223 and 308. Fireformed brass for both would not rechamber. I find that I can resize the brass to the size that will fall in and out of a Lyman case gauge, but still not chamber. I must tweak my RCBS FL sizing die down gradually until the case will chamber easily. When I'm doing this final tweaking, am I bumping the neck or sizing the base? I see that FL sizing is a must for my chambers. I intend to buy Redding or Forster dies, so I'm hoping it will streamline the process.

Rate now:
morganlamprechtXFirst Sergeant
Rating: 3.8/5 this site
1312 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

when you use a FL die, it squeezes the body, pushing the shoulder forward before you ever hit the case shoulder with the die...if your die isnt turned in far enough to push the shoulder back after its pushed forward, the brass isnt likely to chamber...if you only neck sized (with a neck die) this wouldnt happen as a neck die doesnt squeeze the case body at all...i have neck sized, but prefer to use FL/neck bushing dies because they feed smoother...i really like the redding type s fl bushing dies and they give great results
Rate now:
SH10FPXPrivate
Rating: 0.0/5 this site
2 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

That makes sense. I was concerned that I was bumping the shoulder too much when trying to size enough to chamber easily. I think I'll go with the Redding type S dies. Heard nothing but good things. Thanks for the feedback.

Rate now:
Tuxedo007XPrivate
Rating: 3.1/5 this site
21 posts this site
Re: Bump vs Full Length Sizing
08/17/2015
(1 vote)

---

I would be very watchful for incipient case head separation! With case head separations, they can range from mild to wild! While it appears that in some cases the attempt is to separate the fly crap from the black pepper, there IS a lot to be gained by correct case resizing. Just throwing the same cases into the Full Length die & sizing away can lead to problems if repeated often enough!

Rate now:
Tuxedo007XPrivate
Rating: 3.1/5 this site
21 posts this site
Re: Bump vs Full Length Sizing
08/17/2015
(1 vote)

---

ZenBiker990 wrote:

A1J04 wrote:

This has been entertaining as hell. lmao. We've all been there and over thought this, for ions. We're some crazy little monkeys who just like to make stuff hard on ourselves.

Ya, just slam the Full Length Sizing Die in the press, screw it down till it makes contact with shell holder and then back it off a few turns. Place a "FIRE FORMED" case with it's neck and shoulder either blackened with a sharpy or smoke it with a candle into the shell holder, run it all the way up and see if the markings are say around half way down the neck. Turn it down a tad more and do it again till you've sized the neck and touched/bumped the shoulder back .002 bolt/.004 other. You'll drive yourself crazy if you try to figure too much of this out at one time, especially when you think you're making your case shorter but it's GROWING ha.

Too much fun.​

The force is strong with this one. Wise, he is.



Amen!​

Rate now:
NameEnoughXGunny Sergeant
Rating: 3.2/5 this site
571 posts this site
Re: Bump vs Full Length Sizing
08/17/2015

---

Tried bump neck sizing and it's not for me.

I shoot F-TR class and full length size. Most of the F-class shooters I converse with also full length size to get a consistent case.

Of course I also do other things - I anneal each time I reload. I know guys that anneal before and after processing. I also turn necks and trim each reload every time. I also check concentricity each time and I use a 309 expander mandrill to reduce neck tension. So I am not shy of doing a little extra work.

Rate now:
lrgrendelXSergeant
Rating: 3.0/5 this site
173 posts this site
Re: Bump vs Full Length Sizing
08/17/2015

---

New 6.5 Creedmoor bolt gun.

Using Hornady brass, hoping to get 5 or 6 reloadings.

Would love one of those Forster should bump/ bushing dies but it is not made in this caliber.

Don't want to over work the brass????

What are my choices?? Don't mean to take over the thread.....
Rate now:
ArmyJerryXFirst Sergeant
Rating: 3.3/5 this site
3725 posts this site
Re: Bump vs Full Length Sizing
08/30/2015

---

Get the lee collet die and a set of whidden dies, non bushing. You should get a hornady headspace gauge set to measure the before and after sizing to make sure you are not over sizing. FYI you will get loose pockets before you get case head seperation with the 6.5 creedmoor Horn brass.

lrgrendel wrote: New 6.5 Creedmoor bolt gun.

Using Hornady brass, hoping to get 5 or 6 reloadings.

Would love one of those Forster should bump/ bushing dies but it is not made in this caliber.

Don't want to over work the brass????

What are my choices?? Don't mean to take over the thread.....​

Rate now:

 

[Guest]

bigedp51XGunny Sergeant
Rating: 2.9/5 this site
768 posts this site
Re: Bump vs Full Length Sizing
09/03/2015
(3 votes)

---

Shifu wrote:
I understand the concepts. But can any FL die be used to bump?​

Any full length die can be used to "bump" the case shoulder and "bump" is just a word. The term bump refers to minimal shoulder setback when resizing and not setting your full length die as per the instructions. I have a Lee .223 full length die that will bump, shove, push the shoulder back .011 shorter than my chamber headspace if the die makes hard contact with the shell holder and the press cams over.

Below, "bump" for a bolt action would be .001 to .002 below the red dotted line. And if you set the die up per the instructions and having the press cam over the shoulder would be at the green dotted line. Bump is a word used to explain "minimum" shoulder set back.

My neck sizing bushing die below "bumps" the shoulder when needed and does not touch the body of the case.

Below is a .303 British case forming and trim die with a fired case inside the die, the body and neck of the case are not touching the inside of the die. And my little finger is keeping the case from falling out of the die. And by adjusting this case forming die up or down I can "bump" only the shoulders of my fired cases when they become hard to chamber when neck sizing only. The case forming dies are used to form cases and the inside of the die is approximately .010 larger in diameter than the standard die, and why it does not size the body of a fired case.

And if after reading this if we meet on the street we could say we "bumped" into each other. But if I hit you with my car in the street I would push your shoulder back as far as it would go. And that would be the green dotted line the medical examiner would put on your over worked compressed shoulder.

Rate now:
HHarkeX376 MONTHS
Premium Member
Sergeant
Rating: 3.0/5 this site
410 posts this site
Re: Bump vs Full Length Sizing
09/09/2015

---

two points

1. You can use one set of dies without changing the settings/lock ring for two or more guns with different headspace by buying a set of Skip Otto shims from Sinclair internation ($13) and headspacing the die on the shortest case and using the appropriate shims for the longer cases. They just go under the die and are from .001 to .010. cheap, accurate and work great for multiple guns and one set of dies.

2. Several commented that IF you set the die flush with the shellholder to get cam over you can push back the shoulders quite a bit. I have seen .015. You can push back to the point that the case will not chamber as it pushes the side of the shoulder/case joint out too much. I have seen this happen on three occasions. Just back the die off as mentioned and come down 1/4 turn until you get the .002 shoulder bump you are looking for.
Rate now:
XringerXPrivate
Rating: 3.0/5 this site
10 posts this site
Re: Bump vs Full Length Sizing
09/29/2015
(1 vote)

---

I'm going to have to disagree with the "Full Size and go" option. I own the Forster Neck/Bump die, and I can tell you from experience that you will get many more loads from your cases if you neck/bump as opposed to FL resizing. That's not to say you should never FL size. As a rule of thumb, I will FL resize every 5th load. This pic is a perfect example of case head separation. Remember, it's very important to clean then inspect cases BEFORE reloading them. There is such a thing as overworking your brass. Each time you size it it becomes invariably weaker. There is another way to check for early separation using the "coat hanger" method. Take pliers and turn a 90 on the end that small enough to fit in the case. Run the edge of the coat hanger up the side of the case from the bottom. If you feel an indention in the head of the case a few mils up the wall, discard the case and move to the next one. It's true that 308 cases can be fired well into the double digits. but I also have WSSM cases that have reached double digits as well. Tis better to be too critical of spent cases than have a head separate in the field.

Rate now:
okiefiredXFirst Sergeant
Rating: 0.0/5 this site
1195 posts this site
Re: Bump vs Full Length Sizing
10/27/2015

---

I'm with Xringer. I've used the bump/bushing die for years with great results. Keep track of your brass and use it in the same BA rifle and no need to FL resize. If you do, you're working the brass for no reason. That said, I FL size everything for auto loaders but to be honest, don't know if it's always needed. For precision, case prep is a must, i use Lapua and Norma for that, it's about consistency. Something I haven't seen mentioned in this thread is neck turning....which helps ensure proper tension, concentricity and feeding. True it's not complicated but like everything, consistency in ammo takes more time and better quality equipment.

Rate now:
Elfster4321

XFirst Sergeant
Rating: 2.9/5 this site
1330 posts this site
Re: Bump vs Full Length Sizing
11/03/2015

---

I just full length resize with a shoulder bump. Easy and accurate for me... Using Redding national match 3die sets

.001 to .002 for bolts
.003 to .005 for semi autos

Rate now:
JigStick

XSergeant
Rating: 3.3/5 this site
471 posts this site
Re: Bump vs Full Length Sizing
11/06/2015 Last edited 11/06/2015 by JigStick

---

I learned to reload by some top notch short range bench rest shooters. When it comes to hunting and tactical guns they always full length size. Having the cases reliably chamber is what is most important. FL sizing and bumping the shoulder .001-.003 for a hunting or tactical rifle is not going to make a difference when it comes to accuracy, precision, or case life. What it has the potential to do is cause a round not to chamber at the worst time ever. The idea that it will extend case life is a myth. You are still working the brass.

Now. Do I FL size and bump shoulders in my hunting rifles? Sometimes. Depends on what and where Im hunting. For western PA deer hunting I will. Because Im 100% certain Ill be needing only 1 shot. usually I only put 1 in the gun. And If I'm using one of my BAT single shot actions even more so. And why do I do it? Because I set up my dies the first time I used them to accomplish that. Using "Skips Die Shims" from SinClair Int. Thats the only reason.

When I'm hunting black bear with a BAT or Stiller repeater in 10ft tall mountain laurel, hell no. Ill FL size and bump that shoulder back all the way. Not worth the risk of not having one chamber because I tried to get cute reloading and keep SB to a minimum. A wounded or charging blackbear may require a quick follow up. Worst time for a round not to chamber.

Now when Im with my buddys at bench rest matches, or shooting 6BR's and 6PPCs, hell yeah. I want that case snug and tight in the chamber. When you're shooting bugholes like that it may make a noticeable difference in group size.
Rate now:
okiefiredXFirst Sergeant
Rating: 0.0/5 this site
1195 posts this site
Re: Bump vs Full Length Sizing
11/08/2015

---

It's true, all sizing dies "work" brass. Bench rest shooter or not, to insinuate they all work it the same way or as aggressively is just plain wrong. it's common scence, why work it more than need be? In 30+ years of reloading, I've never had a round I couldn't chamber sized by a bump/neck sizing die in the rifle it was reloaded for. Everyone knows bench rest shooters and they're just like the rest of us, they all have opinions just like they all have ass..... Very few opinions trump personal experience with me.

Rate now:
VooDoo62XPrivate
Rating: 3.0/5 this site
19 posts this site
Re: Bump vs Full Length Sizing
11/21/2015

---

Is it possible to have a bolt rifle chamber that is so tight in tolerance that you have to FL size every time you reload the fired cases? I neck size the cases for my .308 and they are tight in the chamber they were fired from once reloaded. New rifle for me, I have never had this problem before. The cases are fully prepped and polished, trimmed, deburred, chamfured, etc. The case alone fits fine but when a bullet is seated it gets hard to close the bolt no matter what depth the bullet is seated at. The outside of the case will have scrubbing marks on it when removed from the chamber when trying the ammo for size.

Rate now:
5RWill

XFirst Sergeant
Rating: 3.4/5 this site
4388 posts this site
Re: Bump vs Full Length Sizing
12/07/2015

---

I declare this thread resurrected! Hehe



Anyhow so which does everyone use? For your field rifles i.e. match/hunting do you all FL resize for reliability? I'm thinking about giving a forster bump die a shot to try and conserve brass life maybe tighten the groups up a tad.

Rate now:
gunman40XPrivate
Rating: 0.0/5 this site
14 posts this site
Re: Bump vs Full Length Sizing
12/07/2015

---

anyone ever trie the RCBS "X" die? I know it's supposed to stop the case from lengthening, but does it full length size?

Rate now:
Nightforce123X19 MONTHS
Premium Member
Sergeant
Rating: 3.1/5 this site
240 posts this site
Re: Bump vs Full Length Sizing
12/07/2015

---

For my 7mm08 I use a lee collet die to neck size, a Redding body die to size the body and push the shoulders back .002. I use a rcbs headspace gage to check how far I pushed the shoulders back. I use this all in a Forster co-ax press. It makes for very accurate and straight rounds.
Rate now:

 

[Guest]

MikehotelXSergeant
Rating: 3.2/5 this site
324 posts this site
Re: Bump vs Full Length Sizing
12/18/2015

---

thanks guys,,

this discussion answers questions I asked in another thread...
Rate now:
honesthopX23 MONTHS
Premium Member
Sergeant
Rating: 3.1/5 this site
110 posts this site
Re: Bump vs Full Length Sizing
01/06/2016

---

I resolved much brass attrition, poor consistency in OAL, some accuracy issues, mostly vertical stringing, and headspace differences by learning proper case annealing. that brass has gotta go somewhere when we move it, as it gets harder. my $.02 on 'just screw the die in to the shell holder and FLS. the whole point of checking headspace is to gain accuracy improvement and case life. getting new brass where it fits takes at least 2 fireforms ,to me anyways, and just FLS 'all the way', even annealed brass will prematurely fail when numerous firings with long headspace and continued FLS all the way over and over WILL minimize case life. of my many different cartridges, 17's to .458, some I will anneal every 2 firings, others 5-6. I don't like tossing fully prepared brass away. my Swift brass goes 20 firings plus from care. the swift was designed as a dragster and that's me. it took me awhile to say 'self, you now understand headspace and it's related issues'. do I tho ? when shoulder below neck is against the same shoulder inside the firing chamber, the case head [primer end] should be ideally .002''-003'' from bolts face and walls. that is headspace. when the cartridge fires, it expands and seizes the chamber walls with 50,000 #'s of internal pressure or more. the brass expands lengthwise also so that .002''-.003'' clearance is gone to 0. bullet leaves, pressure is released, brass will spring back .002'' or so. custom chamber/dies can be 'matched' with custom clearance's, only neck sizing is done for many, many shots and bumped back when needed. some brass is fired up to 200 time with very minimal brass working done. I definitely believe controlled headspace clearances are worth it. every little bit helps to your goal.

Rate now:
Tristian19

XGunny Sergeant
Rating: 3.2/5 this site
598 posts this site
Re: Bump vs Full Length Sizing
01/19/2016

---

Before I went with BODY and NECK dies I successfully used FL Die to BUMP, as well as, FL Size case.

FWIW: I use Redding Dies.

Safe shooting...





Rate now:
SigSavageXPrivate
Rating: 0.0/5 this site
7 posts this site
Re: Bump vs Full Length Sizing
01/26/2016

---

I am brand new to reloading and this whole "sizing" thing has had me stumped. This thread has been very helpful, especially the pictures to hel me visualize what is going on in the sizing process. I have just been following the directions that came with my dies for set up (turn die down until it touches shell holder then back off a little bit), putting the brass in, and then pulling the lever down. I had an idea what the process was doing, but didn't fully understand all the different pieces of the process.

So, I'd like to please clarify a couple things so that I will do the correct process in the future:

1) get a headspace gauge. This will tell me the length of my chamber is by measuring the fired, unsized cartridge to within about .003" due to spring back. A once fired "new" piece of brass should've be use for this.

2) get a neck sizing die to just reform the neck of the case only so I can get the bullet in for seating. Neck sizing increases cartridge life.

3) every fifth reloading of a case, use my full length sizing die.

4) use a blowtorch and anneal the cartridge neck every fifth reloading. Do this before sizing.



Now, how do I use the info I get from the headspace gauge? When do I know if my cartridge needs to have its shoulder bumped back? Do I just go by the general feel of when I chamber the cartridge before shooting? If it is difficult to chamber do I assume it is because the shoulder is too far forward? Do I then measure the length of that cartridge using my headspace gauge? If it is too long then I need to bump the shoulder?

Also, when using the headspace gauge is it safe to assume that the brass measurement is an accurate representation of the gun's actual headspace as long as the cartridge can be chambered easily? Do I need to also do this test I've read about people removing the firing pin from their bolt and letting it fall into place, and if it goes 2/3 of the way on its own then the cartridge is the correct size?

Last, when it comes time to bump the shoulder back, how do I know how much more to screw the die down? Once it hits the shell holder and cannot go any further and it is not bumping the shoulder, what then? Or is this actually an issue? Do FL dies generally over-bump the case, requiring a person to actually back off the die and screw it out? If you are doing this, how do you know how much to back it off? Is it by ill and error using multiple cases?



thanks for any help.

Rate now:
Tristian19

XGunny Sergeant
Rating: 3.2/5 this site
598 posts this site
Re: Bump vs Full Length Sizing
01/28/2016 Last edited 01/28/2016 by Tristian19

---

I am FAR from a reloading expert so take anything I convey with a grain of salt. With that said:

1) Following link is to one of my head space gauges: Feel free to view product overview: midwayusa.com/product/727107/le-wilson-case-length-headspace-gage-338-lapua-magnum

2) I FL or BS size all my cases and not just NS << Not saying NS will not be sufficient for your caliber/situation

3) See #2

4) I would Anneal every one or two (Just me). Yes, anneal BEFORE sizing



When do I know if my cartridge needs to have its shoulder bumped back?

A: Depending on caliber I bump 0.001 to 0.003 evertime

If it is difficult to chamber do I assume it is because the shoulder is too far forward?

A: Definitely can be ONE sign

Do I then measure the length of that cartridge using my headspace gauge?

A: I would suggest you consider running ALL your cases through gauge every time, at least UNTIL you find it is no longer needed

If it is too long then I need to bump the shoulder?

A: Always use HS Gauge properly to rule out

Also, when using the headspace gauge is it safe to assume that the brass measurement is an accurate representation of the gun's actual headspace as long as the cartridge can be chambered easily?

A: Not qualified to answer. I also would NOT assume anything

Do I need to also do this test I've read about people removing the firing pin from their bolt and letting it fall into place, and if it goes 2/3 of the way on its own then the cartridge is the correct size?

A: Not familiar with this method as described

Last, when it comes time to bump the shoulder back, how do I know how much more to screw the die down?

A: Call Die maker and confirm how they suggest

Once it hits the shell holder and cannot go any further and it is not bumping the shoulder, what then?

A: Call Die maker and confirm how they suggest

Or is this actually an issue?

A: Cannot answer with certainty

Do FL dies generally over-bump the case, requiring a person to actually back off the die and screw it out?

A: Yes, IF performed incorrectly

If you are doing this, how do you know how much to back it off?

A: I measure, bump down and make sure brass has NO issues when I close bolt

Is it by ill and error using multiple cases?

A: I ONLY use same case manufacturer per rig (If you are referring to using different manufacturers) NOT saying you cannot



Do not take following negative, do some more research as answers are available. A lot of above is trial and error as well.

NOTE: Above are my thoughts and am NOT trying to say my way is BEST way. What I do works for me as my results display consistent 0.5 MOA prints. Simply sharing and possibly help out as that is what I thought SH is here for

Safe shooting...







Rate now:
BuzzBoss915

XFirst Sergeant
Rating: 0.0/5 this site
1266 posts this site
Re: Bump vs Full Length Sizing
01/29/2016

---

Shifu wrote:
I understand the concepts. But can any FL die be used to bump?​

I think the answer is yes?

You may understand the concepts, but what really matters is your motive, or objective. Everyone has a theory, but you will draw your own conclusions based on exactly how anal you become. Bumping the shoulder is a very satisfactory resizing method, once you get the hang of it. What you should look for, (on an assembled round) is a slight resistance closing the bolt. BB

Rate now:
honesthopX23 MONTHS
Premium Member
Sergeant
Rating: 3.1/5 this site
110 posts this site
Re: Bump vs Full Length Sizing
03/11/2016

---

spawno1815v- instead of buying an expensive bump custom bump die, if an acceptable chamber die has the same shoulder angle [std chambering for a gunshow used die set for $20 or so]. buy it, cut it off to close correct length, flare a little for brass entry protection, and presto, a head space bump die less the body size aspect that ends there. if a lathe is handy, part it off, trim it to proper length. if you have chamber reamer, make your own bump die from 1144 stress-proof, or 12L, H20 quench. either are very simple to harden a little for great longevity. I hope I got that right. make sure of a good finish tho. I like bumpers for THE chambering being bumped. I have used 1018, in a salt brine solution. surface hardened a cat can't scratch. you just have to have the nice finish and heat treatment ss wrap,. the el cheapo method. [I've made 100's of brine hardened do-dads from mild hot rolled steel for many repairs from that method. had a Wyoming rig welder working for me on a turnaround that made really nice spurs, belts, quirks, etc., cowboy stuff. cheapest quirks he had were $700, 20 years ago spurs $2,000 . he had a PILE of hot rolled rawls[?] some buddy he had at IR cut 'em on their water jet. he'd file mark 'em so they'd looked old and brine harden to ring like clint eastwood walking down the boardwalks. just plain cool and a very useful learning info. table salt in water.--good luck!

Rate now:
RwnielsenXPrivate
Rating: 3.0/5 this site
36 posts this site
Re: Bump vs Full Length Sizing
06/10/2016

---

lrgrendel wrote: New 6.5 Creedmoor bolt gun.

Using Hornady brass, hoping to get 5 or 6 reloadings.

Would love one of those Forster should bump/ bushing dies but it is not made in this caliber.

Don't want to over work the brass????

What are my choices?? Don't mean to take over the thread.....
I have a Forster 6.5 Creedmoor bump- neck die. Got it at Natchez I believe, along with a Wilson case gauge​

Rate now:
waynemacXSergeant
Rating: 3.1/5 this site
179 posts this site
Re: Bump vs Full Length Sizing
08/17/2016

---

I use mostly Redding full length bushing dies and have good success with them. As has been mentioned, when you size and bump your shoulder, the brass gets displaced. That's why you have to trim brass from time to time. The question a bout brass spring back... As brass work hardens, think fire / size, fire / size, it gets harder and will spring back when you size. The solution is to anneal your brass. This helps with consistent bullet pull as well as keeping your sizing consistent.
And for the record, you ALWAYS full length size your brass. Neck sizing has no place when shooting a repeater, heck I full length size all my benchrest cartridges as well. Also, just a heads up, Hornady makes a nice custom bushing die that uses Redding and Wilson bushings. I have one of these for my .220 Beggs.
Wayne

 

[Guest]

I just want to know why you have two 6.5 Creedmoors!
If the brass doesn't chamber then you have to size it correctly.
If the regular f/l die doesn't do it, but the small base does, you've solved your problem. Congrats!

Rate now:

 

[DynamicAccuracy]

I'd just full length size. Never messed with shoulder bump and I've got pretty good results out of full length sizing

 

[LVLAaron]

I use the Redding precision shell holders. They come in a set of 5 or 6 and in various heights. Use the right one so you resize the least but the brass still fits your chamber. They're expensive but I don't like the crap about backing out the die, etc. Just not as repeatable. For my 6.5 Streetcred bolt rifle I use the +.010 holder - So it adds 10 thou to the headspace.

 

[BountyHunter]

IF you want a custom fit and die that properly sizes then there is a way to get it without going expensive custom. Jim Carstenson at JLC Precision 563-212-2984 will make one out of a Redding body die.

You need to send him 10 cases fired 3x with full power loads. He will custom hone the body die to size for your chamber, convert the body die to bushings also so you can control the necks. Last time I had it done was $80 and 2-3 week turnaround. Might be more now but call him.

 

[xsn10s]

I've done both with good results. Now I am going to try X-Dies to cut down on trimming. Initially it looked pretty good. But a couple of moves and now the brass is all mixed up so I'll have to start all over again.

 

[ranger43]

I use the Forster Shoulder bump dies, works excellent in my 243 match chamber. I can bump 2-4 times before I FL size.

 

[Innovative]

I firmly believe in full length resizing . . . . always. Most shooters are surprised to find that benchrest shooters use full length dies. However, they know how to set their die height accurately. This is more important than most handloaders realize.

I use the Digital Headspace Gauge, and all my handloads fit far closer than any loads made by just following the instructions that come with resizing dies. No other method could be quicker or easier.

Remember: Reliable chambering is never optional. For consistent accuracy, your handloads need .001" clearance at the shoulder and at the diameter of any tapered case wall.

 

[ranger43]

I use the Shoulder Bump dies on two of my rifles. It works extremely well in my .243 Criterion Match chamber. Not as good in my 22 250. I think it matters a lot on your chamber and headspacing. My 243 is headspaced tightly and does not take much to adjust. So otherwise, I believe full length resizing is usually best.

 

[xsn10s]

I bump, FL size, neck size only, and on occasion use an X die.

 

[ranger43]

I like the bump mainly with two rifles who don't seem to do anymore than simply stretch the shoulder.

 

[PracticalTactical]

I firmly believe in full length resizing . . . . always. Most shooters are surprised to find that benchrest shooters use full length dies. However, they know how to set their die height accurately. This is more important than most handloaders realize.

I use the Digital Headspace Gauge, and all my handloads fit far closer than any loads made by just following the instructions that come with resizing dies. No other method could be quicker or easier.

Remember: Reliable chambering is never optional. For consistent accuracy, your handloads need .001" clearance at the shoulder and at the diameter of any tapered case wall.

I assume you mean 100 yard bench rest shooters. At that distance they are not really concerned with consistent velocity as a 1000 yard shooter will be.

To my way of thinking.. as a long range shooter... that anything that can be done to increase muzzle velocity and make muzzle velocity more consistent is a positive move.

I think of it this way, and have done a fair amount of chronograph testing to support my belief that fire formed cases being larger can support a slightly heavier powder charge so I can hit a higher muzzle velocity for one thing...

Furthermore, because the case already fits the chamber wall, that little to no energy is lost to blowing the case out to fit the chamber, so that energy is used more efficiently toward moving the bullet down the barrel.

Furthermore, since energy is not lost to blowing out the brass... the velocity is more consistent with fire formed cases... just one less variable... or at least a more reduced variable.

Certainly there is some middle ground available here as you can do a partial shoulder bump with a partial body resize. That can obviously be done by unscrewing the die a bit, or using the spacer type shell holders that Redding makes in 0.002" increments.

BTW... if you guys are curious how much side wall resize you are getting, you can easily make a ring gage by drilling a hole in a piece of steel that is close in size to the datum point on the side wall where you want to check. In this case you'd be checking contact against a sharp corner.

If you happen to have a chambering reamer, you can run that into the hole (pre drill smaller) to create the matching side wall angle. This would be more accurate and easier to work with.

Keep in mind the measurement is long axis against a mild angle, so you would need the side wall angle and translate the linear value to the diameter which would need you to do a little trigonometry.

 

[b6graham]

if you arent full length sizing you're doing it wrong.

way to necro a shit thread

i hear the best way to add velocity is to stake your rifle into the ground and tie strings to a rock though so what do i know

 

[ranger43]

I only use shoulder bump in my 243, it works wonderfully there. Normally I use a FL die and work the shoulder carefully. I believe shoulder bump has it's place

 

[ThePretzel]

I use only a shoulder bump die when reloading for my 6BR for two reasons, neither of which has anything to do with the accuracy of the loaded rounds:

1. I'm lazy and shoulder bump resizing allows me to skip lubricating the cases before sizing and cleaning after sizing
2. With my 6BR the brass never expands enough near the case head to cause sticky cases if I don't full length resize, at least not within the number of firings my brass goes through over the life of a barrel (I buy new brass with my new barrels)

It has nothing to do with me thinking it will make my loads more or less accurate to full length resize or shoulder bump resize. It has everything to do with saving time and effort when reloading so that I don't have to deal with case lube. If I was reloading a hotter cartridge or loading my BR hot enough to cause significant case expansion I would full length resize - I do it every time for the 6.5 Creedmoor since I like hot loads in that cartridge and it needs it after 2-3 firings even with standard loads.

I just don't bother with my BR since I haven't noticed any problems with accuracy or feeding and it's less work to not full length resize.

 

[Datsrboi]

I use redding FL dies that allows me to control bump my shoulder. I try not to bump it too much as that will just wear out the brass. Has work wonders for me and my brass life has been amazing.

 

[AManWearingAHat]

I'm going to ask the stupid question, why the preference for bump or FL sizing over neck sizing? My practice has generally been to neck size as much as possible for my military bolt actions and the couple of scoped savages I own to increase brass life.

 

[XLR308]

I'm going to ask the stupid question, why the preference for bump or FL sizing over neck sizing? My practice has generally been to neck size as much as possible for my military bolt actions and the couple of scoped savages I own to increase brass life.

For a rifle that is a range queen and kept squeaky clean neck sizing is fine.
For a hard use rifle used extensively for hunting or field type competitions were it could get pretty dirty from fine dust and dirt or a dirty chamber from high round count you can run into problems.
Add to that a custom rifle with tighter chamber specs than a off the shelf or mil surplus rifle and it can compound the issue.
If the chamber and FL sizing die are properly matched up you aren't loosing any brass life over neck sizing as long as the brass is being sized properly and not being overworked.

 

[AManWearingAHat]

For a rifle that is a range queen and kept squeaky clean neck sizing is fine.
For a hard use rifle used extensively for hunting or field type competitions were it could get pretty dirty from fine dust and dirt or a dirty chamber from high round count you can run into problems.
Add to that a custom rifle with tighter chamber specs than a off the shelf or mil surplus rifle and it can compound the issue.
If the chamber and FL sizing die are properly matched up you aren't loosing any brass life over neck sizing as long as the brass is being sized properly and not being overworked.

Ah. I suspected that was the answer. Currently most of my rifles are range queens. I will keep what you said in mind though, thank you!

 

[XLR308]

Ah. I suspected that was the answer. Currently most of my rifles are range queens. I will keep what you said in mind though, thank you!

Most of mine are to and I do neck size for some of them.
If the chamber seems a bit on the loose side of the tolerance then yes neck sizing will prolong brass life if the FL die is overworking the brass.
I have a Tikka 270win that pretty much everything I've shot out of it there is a slight bulge in front of the case head.
It shoots very tight even when the light weight barrel heats up but I don't expect great brass life from it if FL sized so mainly just shoot factory ammo from it.

 

[highfinblue]

spawnof918vXFirst Sergeant
Rating: 2.6/5 this site
3755 posts this site
Re: Bump vs Full Length Sizing
07/18/2015
(1 vote)

---

SB resizing does not affect accuracy or case life. I SBFL size for everything, taking care to bump the shoulder minimally. I am fortunate my semi-auto chamber is within .001" of my bolt gun chamber in terms of headspace. But a FC case sized that way will last in excess of 20 firings with moderate (50KPSI) loads.
Rate now:
ZenBiker990

X64 MONTHS
Premium Member
Sergeant
Rating: 3.2/5 this site
319 posts this site
Re: Bump vs Full Length Sizing
08/12/2015
(3 votes)

---

A1J04 wrote:​

​

This has been entertaining as hell. lmao. We've all been there and over thought this, for ions. We're some crazy little monkeys who just like to make stuff hard on ourselves.​

​

Ya, just slam the Full Length Sizing Die in the press, screw it down till it makes contact with shell holder and then back it off a few turns. Place a "FIRE FORMED" case with it's neck and shoulder either blackened with a sharpy or smoke it with a candle into the shell holder, run it all the way up and see if the markings are say around half way down the neck. Turn it down a tad more and do it again till you've sized the neck and touched/bumped the shoulder back .002 bolt/.004 other. You'll drive yourself crazy if you try to figure too much of this out at one time, especially when you think you're making your case shorter but it's GROWING ha.​

​

Too much fun.​

The force is strong with this one. Wise, he is.

Rate now:
SH10FPXPrivate
Rating: 0.0/5 this site
2 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

I am relatively new to reloading but not a full novice. This thread is interesting to me as I had problems with resizing for my Savage 223 and 308. Fireformed brass for both would not rechamber. I find that I can resize the brass to the size that will fall in and out of a Lyman case gauge, but still not chamber. I must tweak my RCBS FL sizing die down gradually until the case will chamber easily. When I'm doing this final tweaking, am I bumping the neck or sizing the base? I see that FL sizing is a must for my chambers. I intend to buy Redding or Forster dies, so I'm hoping it will streamline the process.

Rate now:
morganlamprechtXFirst Sergeant
Rating: 3.8/5 this site
1312 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

when you use a FL die, it squeezes the body, pushing the shoulder forward before you ever hit the case shoulder with the die...if your die isnt turned in far enough to push the shoulder back after its pushed forward, the brass isnt likely to chamber...if you only neck sized (with a neck die) this wouldnt happen as a neck die doesnt squeeze the case body at all...i have neck sized, but prefer to use FL/neck bushing dies because they feed smoother...i really like the redding type s fl bushing dies and they give great results
Rate now:
SH10FPXPrivate
Rating: 0.0/5 this site
2 posts this site
Re: Bump vs Full Length Sizing
08/14/2015

---

That makes sense. I was concerned that I was bumping the shoulder too much when trying to size enough to chamber easily. I think I'll go with the Redding type S dies. Heard nothing but good things. Thanks for the feedback.

Rate now:
Tuxedo007XPrivate
Rating: 3.1/5 this site
21 posts this site
Re: Bump vs Full Length Sizing
08/17/2015
(1 vote)

---

I would be very watchful for incipient case head separation! With case head separations, they can range from mild to wild! While it appears that in some cases the attempt is to separate the fly crap from the black pepper, there IS a lot to be gained by correct case resizing. Just throwing the same cases into the Full Length die & sizing away can lead to problems if repeated often enough!

Rate now:
Tuxedo007XPrivate
Rating: 3.1/5 this site
21 posts this site
Re: Bump vs Full Length Sizing
08/17/2015
(1 vote)

---

ZenBiker990 wrote:​

A1J04 wrote:​

​

This has been entertaining as hell. lmao. We've all been there and over thought this, for ions. We're some crazy little monkeys who just like to make stuff hard on ourselves.​

​

Ya, just slam the Full Length Sizing Die in the press, screw it down till it makes contact with shell holder and then back it off a few turns. Place a "FIRE FORMED" case with it's neck and shoulder either blackened with a sharpy or smoke it with a candle into the shell holder, run it all the way up and see if the markings are say around half way down the neck. Turn it down a tad more and do it again till you've sized the neck and touched/bumped the shoulder back .002 bolt/.004 other. You'll drive yourself crazy if you try to figure too much of this out at one time, especially when you think you're making your case shorter but it's GROWING ha.​

​

Too much fun.​

The force is strong with this one. Wise, he is.​

​

​

​

Amen!​

Rate now:
NameEnoughXGunny Sergeant
Rating: 3.2/5 this site
571 posts this site
Re: Bump vs Full Length Sizing
08/17/2015

---

Tried bump neck sizing and it's not for me.

I shoot F-TR class and full length size. Most of the F-class shooters I converse with also full length size to get a consistent case.

Of course I also do other things - I anneal each time I reload. I know guys that anneal before and after processing. I also turn necks and trim each reload every time. I also check concentricity each time and I use a 309 expander mandrill to reduce neck tension. So I am not shy of doing a little extra work.

Rate now:
lrgrendelXSergeant
Rating: 3.0/5 this site
173 posts this site
Re: Bump vs Full Length Sizing
08/17/2015

---

New 6.5 Creedmoor bolt gun.

Using Hornady brass, hoping to get 5 or 6 reloadings.

Would love one of those Forster should bump/ bushing dies but it is not made in this caliber.

Don't want to over work the brass????

What are my choices?? Don't mean to take over the thread.....
Rate now:
ArmyJerryXFirst Sergeant
Rating: 3.3/5 this site
3725 posts this site
Re: Bump vs Full Length Sizing
08/30/2015

---

Get the lee collet die and a set of whidden dies, non bushing. You should get a hornady headspace gauge set to measure the before and after sizing to make sure you are not over sizing. FYI you will get loose pockets before you get case head seperation with the 6.5 creedmoor Horn brass.

lrgrendel wrote: New 6.5 Creedmoor bolt gun.

Using Hornady brass, hoping to get 5 or 6 reloadings.​

​

Would love one of those Forster should bump/ bushing dies but it is not made in this caliber.​

​

Don't want to over work the brass????​

​

What are my choices?? Don't mean to take over the thread.....​

Rate now:

This was all very interesting and I do not consider myself an expert by any stretch, but I've been reloading for close to forty years with no major mishaps, (knock on wood); I am not a high volume shooter as I'm sure some of you are, but I do shoot quite a bit, all my own loads. I only use one set of dies for each rifle, I only use the best brass I can afford again in one rifle, and I neck size using whatever brand of dies i have for that rifle, until it starts getting really tight to chamber a round and then full length resize and then repeat. Works for everything I own almost, but that doesn't mean there hasn't been some issues along the way like the freaking 28 Nosler that I try to bump the shoulders back every time with Whidden dies and then try and not go insane with how quickly I start seeing pressure lol

 

[PinesAndProjectiles]

What kind of pressure signs are you seeing when you're bumping shoulders back?

You COULD be bumping them too far. This causes the case to essentially "float" within the chamber. When you pull the trigger, the firing pin has to push the case shoulder into the chamber before it expels enough energy to ignite the primer.

Are you measuring the datum point on the shoulder of the case both before and after FL sizing? How far are you bumping them?

I would not rule out overcharging the case, as I have no idea what your load is, but it is something worth considering.

 

[highfinblue]

What kind of pressure signs are you seeing when you're bumping shoulders back?

You COULD be bumping them too far. This causes the case to essentially "float" within the chamber. When you pull the trigger, the firing pin has to push the case shoulder into the chamber before it expels enough energy to ignite the primer.

Are you measuring the datum point on the shoulder of the case both before and after FL sizing? How far are you bumping them?

I would not rule out overcharging the case, as I have no idea what your load is, but it is something worth considering.

The bolt just gets a little heavy to lift. I’m super cautious so at any sign of pressure I’m getting rid of the carbon that builds at the throat. Ryan Pierce built the rifle it it very accurate, but a less temperamental caliber would have been a better choice

 

[highfinblue]

The bolt just gets a little heavy to lift. I’m super cautious so at any sign of pressure I’m getting rid of the carbon that builds at the throat. Ryan Pierce built the rifle it it very accurate, but a less temperamental caliber would have been a better choice

I’m certain I’m close to maximum load, but it’s less than what Ryan usually pushes. I’d be lying if I said I knew the powder charge but I believe it’s 81 gr of N570 behind the 190 gr Berger VLD. It’s like 3150fps and Ryan has gotten over 3200 even close to 3300 which is insane

 

[highfinblue]

I’m certain I’m close to maximum load, but it’s less than what Ryan usually pushes. I’d be lying if I said I knew the powder charge but I believe it’s 81 gr of N570 behind the 190 gr Berger VLD. It’s like 3150fps and Ryan has gotten over 3200 even close to 3300 which is insane

 

[highfinblue]

I’ve spent considerable time talking to Whiddon and I’m only bumping 1-2 thousandths so it’s a fairly tight fit

 

[PinesAndProjectiles]

If you're certain you're close to Max load, then back off. Just because someone else is running a load in their guns, doesn't mean it's safe in yours.

Guns are like humans, every one is different.

I would start over with a new load and disregard what someone told you should work.

But I'm a big fan of having my face and fingers intact. YMMV.

 

[highfinblue]

If you're certain you're close to Max load, then back off. Just because someone else is running a load in their guns, doesn't mean it's safe in yours.

Guns are like humans, every one is different.

I would start over with a new load and disregard what someone told you should work.

But I'm a big fan of having my face and fingers intact. YMMV.

yes sir great advice, but I already did that and had the same results at like 78 grains, almost the starting point of the load. It's really all a guess from here as I don't have all my data in front of me, but this little sweetheart is one of those very cantankerous type, high maintenance you might say. Clean, no pressure, prints tiny groups as far as I can shoot here on my place (500 yards) and no problems, but around the 14th shot weird things start happening. I've ran a bore scope from one end to the other and the only place I can see any buildup is right in front of the throat. The barrel iife on these things is short anyway and after only a hundred rounds or so erosion is clearly visible, but it is a freak as far as ballistics. I can reach a thousand yards in under one turn on my Nightforce NXS. I don't really shoot the thing any more except to hunt. I shoot it once before season to check zero, and then shoot only critters after that. I have several other rifles to keep myself tuned up and that's why I bought the Creedmoor. I'm going to put the same scope on it eventually, and shoot that little bugger until I need a new barrel on it and then do it all over again. I've thought about rebarreling the 28 Nosler, but it works for what I need it to do and will probably outlast me using it like I do.

 

[highfinblue]

yes sir great advice, but I already did that and had the same results at like 78 grains, almost the starting point of the load. It's really all a guess from here as I don't have all my data in front of me, but this little sweetheart is one of those very cantankerous type, high maintenance you might say. Clean, no pressure, prints tiny groups as far as I can shoot here on my place (500 yards) and no problems, but around the 14th shot weird things start happening. I've ran a bore scope from one end to the other and the only place I can see any buildup is right in front of the throat. The barrel iife on these things is short anyway and after only a hundred rounds or so erosion is clearly visible, but it is a freak as far as ballistics. I can reach a thousand yards in under one turn on my Nightforce NXS. I don't really shoot the thing any more except to hunt. I shoot it once before season to check zero, and then shoot only critters after that. I have several other rifles to keep myself tuned up and that's why I bought the Creedmoor. I'm going to put the same scope on it eventually, and shoot that little bugger until I need a new barrel on it and then do it all over again. I've thought about rebarreling the 28 Nosler, but it works for what I need it to do and will probably outlast me using it like I do.

And I did try several other loads as well, hence why I call it all sorts of ugly names. I called the guy that built the action for the gun trying to figure out some details and he said he's heard this frequently about the 28 Nosler, it's just overbored, and very finicky when approaching top velocities.

 

[Vinootz]

•

 

[Rick7353]

Watch video by Eric Cortina. He interviews top 1000 yd shooters at a match and asks the question"full length size or bump the shoulder" 100% said FULL LENGTH SIZE.
Times change mostly by proof. I'm a bench shooter now as I've become disabled and I always full length size using Redding competition S dies.

 

[PracticalTactical]

Watch video by Eric Cortina. He interviews top 1000 yd shooters at a match and asks the question"full length size or bump the shoulder" 100% said FULL LENGTH SIZE.
Times change mostly by proof. I'm a bench shooter now as I've become disabled and I always full length size using Redding competition S dies.

What they conveniently leave out in the video you are referencing is whether or not the FL dies used by top shooters are unmodified over the counter dies or custom manufactured or honed dies that only minimally resize the side wall as well as head space. Regardless of that, they also do not discuss the custom reamer design used to pair the chamber with the die.

Erik speaks with authority and that projects confidence, but there's key information that is not discussed that leaves the audience less educated than they probably realize, even mislead to a degree by the omission of such key details.

They also do not mention who is neck turning or not.

The guys are not top shooters because they happen to FL resize as Erik calls it. They are top shooters for another 50 or so reasons that are too complicated to explain within the attention span of a YouTube audience or forum post.

 

[Dthomas3523]

What they conveniently leave out in the video you are referencing is whether or not the FL dies used by top shooters are unmodified over the counter dies or custom manufactured or honed dies that only minimally resize the side wall as well as head space. Regardless of that, they also do not discuss the custom reamer design used to pair the chamber with the die.

Erik speaks with authority and that projects confidence, but there's key information that is not discussed that leaves the audience less educated than they probably realize, even mislead to a degree by the omission of such key details.

They also do not mention who is neck turning or not.

The guys are not top shooters because they happen to FL resize as Erik calls it. They are top shooters for another 50 or so reasons that are too complicated to explain within the attention span of a YouTube audience or forum post.

Many of them are using straight out the box Redding type S. I know this 100%.

You have almost zero knowledge on these things as evidenced from this post. They aren’t “conveniently” leaving things out. You’re not smart enough to realize loading is extremely simple and the dogma that’s been created the past 20+ years is overly complicated without any real results being produced.

 

[Dthomas3523]

Many of them are not pairing the chamber with the die either. They are using reamers to their desired specs, but many are just using over the counter dies.

 

[fyaman43]

Funny, I was looking at this zombie thread last night.

 

[AZshooterz]

Well I must say I definitely learned a lot reading most of it!

 

[Smittiac]

This is a good one, FL size though .002" bump because it works.

 

[PracticalTactical]

Many of them are using straight out the box Redding type S. I know this 100%.

You have almost zero knowledge on these things as evidenced from this post. They aren’t “conveniently” leaving things out. You’re not smart enough to realize loading is extremely simple and the dogma that’s been created the past 20+ years is overly complicated without any real results being produced.

Some guys are so far behind, they think they are in front.

Jump to 31 minutes into this video and see how little I know.

I guess your going to say Speedy is FOS too now huh?

It's all just a question of what's good enough for each of us. If you cant see the difference, don't bother. If a guy can, and it matters to them, then its something to consider.

 

[Dthomas3523]

Some guys are so far behind, they think they are in front.

Jump to 31 minutes into this video and see how little I know.

I guess your going to say Speedy is FOS too now huh?

It's all just a question of what's good enough for each of us. If you cant see the difference, don't bother. If a guy can, and it matters to them, then its something to consider.

You dumbass. He literally said when he started using full length bushing dies, no one could beat him.

He then says you need a die that matches your chamber. Many chambers match the Redding dies perfectly fine. Many top shooters, including those in the video are using off the shelf Redding dies. As long as they match the chamber. You only need custom dies when you need custom dies. Notice he used the words “if.” You think I haven’t already had these discussions with these guys and others before calling you out?

Swing and a miss again. You’re gone permanently when you do this misinformation shit again.

 

[Dthomas3523]

Many custom reamers don’t change the body taper and therefore don’t require a custom die,

And many chambering don’t have factory dies available. They also need custom dies.

You literally posted a video saying exactly what I told you.

 

[PracticalTactical]

You dumbass. He literally said when he started using full length bushing dies, no one could beat him.

He then says you need a die that matches your chamber. Many chambers match the Redding dies perfectly fine. Many top shooters, including those in the video are using off the shelf Redding dies. As long as they match the chamber. You only need custom dies when you need custom dies. Notice he used the words “if.” You think I haven’t already had these discussions with these guys and others before calling you out?

Swing and a miss again. You’re gone permanently when you do this misinformation shit again.

Too bad... You clearly have a comprehension problem and only see what you want to see.

 

[b6graham]

Too bad... You clearly have a comprehension problem and only see what you want to see.

you're joking right?

 

[ThePretzel]

Apparently the idea of a standardized chamber specification for a particular cartridge is too new and space age of an idea for some people to comprehend. Certainly there couldn't be an organization like SAAMI that keeps a set of standards for the reamers of a particular cartridge that are followed unless a VERY custom reamer is ordered.

Throating doesn't change your chamber at all, because it only affects how the bullet contacts the lands and not how the brass sits in the chamber. As far as chamber reamers goes, the vast majority of shooters - including bench rest shooters, use chamber reamers that match the SAAMI specifications for their cartridge. The resizing dies from Redding, Forster, and others are made based off those same SAAMI specifications. The resizing dies will fit the chamber exactly unless you used a custom non-SAAMI spec chamber reamer.

 

[PracticalTactical]

There's a big difference between production ammunition and ammunition that is hand loaded for competition and the difference has nothing to do with SAAMI.

The reality is that there are tolerances on everything and a lot of confusion about how that is interpreted depending on what you expect to or want to achieve and how each of us define what is acceptable.

Referencing SAAMI is a facile point that feeds a rejection of the concept of doing better than that. SAAMI ensures that a loaded round will fit in any rifle of that cartridge and does not serve to idealize a custom round to each of our specific chambers for the purpose of target shooting.

The reality is that the more case expansion that occurs, the wider the velocity fluctuation will be. Conversely the less case expansion that occurs the lower the velocity spread will occur. There are tolerances on chambering reamers and tolerances on dies and we need to at least realize that much.

It's not even that simple... You also need to consider the free bore diameter clearance and the amount of blow by that occurs before the bullet moves forward far enough to create a gas seal in the bore. If you have a tight freebore, this will have less of an effect than if the freebore is well cleared of the bullet diameter, like most are.

Jump is also a contributing factor and there is a direct correlation to velocity spreads and jump. Too far and you will get more pressure blow by and a wider velocity spread. Too short and you can get velocity spreads because the bullet doesn't hit the rifling while moving where it has inertia on its side to enter the rifling with more consistent force.

Throat angle also influences the result.

In all reality this is less about the truth of what I'm stating and more about our individual abilities and desires to discern the differences.

There's a recent trend in the shooting community to over simplify reloading and that is a disservice to the sport. It seems this seems especially true among "some" PRS shooters who are shooting large plates and if the load is good enough for that, it must therefore be good enough for all others and that is just not true.

I agree with a slight shoulder bump and a slight side wall resize. I do disagree with the naïve claim that is going to happen for everyone with every chamber and every over the counter sizing die.

All that matters is that its good enough for you, but I cant respect pushing that on everyone else as the holy grail for all and the only way it is to be done. If I don't agree with your over simplification, then surely I must be wrong.

 

[ThePretzel]

It's not even that simple... You also need to consider the free bore diameter clearance and the amount of blow by that occurs before the bullet moves forward far enough to create a gas seal in the bore. If you have a tight freebore, this will have less of an effect than if the freebore is well cleared of the bullet diameter, like most are.

Jump is also a contributing factor and there is a direct correlation to velocity spreads and jump. Too far and you will get more pressure blow by and a wider velocity spread. Too short and you can get velocity spreads because the bullet doesn't hit the rifling while moving where it has inertia on its side to enter the rifling with more consistent force.

Throat angle also influences the result.

Congratulations, you just proved exactly how little you know about rifle chambering and the effects of it on reloading. You're busy trying to argue about freebore and throat angle in the middle of a discussion on resizing your brass, despite the fact freebore and throating is completely independent and unrelated to the rifle's chamber dimensions and the reloading of brass for said rifle.