Full length sizing vs. neck sizing for accuracy

[p5200]

When reloading for bolt actions, is it better for accuracy to just neck size or FL. size for best accuracy. I'm using a Forster Coax with the FL. sizing die the instructions say you can screw the die out about 1/8" and it won't FL re size. does that mean it will just re size the neck and not, touch the shoulders? or would I have to get a special die just for neck sizing? Thanks!

 

[Jhnmdahl]

Re: Full length sizing vs. neck sizing for accuracy

The theory is that brass fired in your gun once expands to fit the chamber better, and all you want to do after that is neck size. I'd us a neck sizing die, but bumping a full length die up a little should work as well. Make sure the bolt closes on a resized shell before doing a bunch and you'll be fine,

John

 

[p5200]

Re: Full length sizing vs. neck sizing for accuracy

Thanks, I'll check into a neck sizing die also.

 

[Mark Walker]

Re: Full length sizing vs. neck sizing for accuracy

Neck sizing for accuracy is a myth.... If you have a good fit between your f/l die and your chamber, that is all you need for outstanding accuracy.

 

[nhassey48]

Re: Full length sizing vs. neck sizing for accuracy

I would invest in a shoulder bump gauge from Sinclair international. They are awesome. I would neck size until it is hard to chamber a fire case, then I would bump the shoulder back .001 to .003. The less you move the brass the better. i would say .002 bumped would be good. Then, repeat the process with neck sizing until it requires a shoulder bump again. Some reloaders bump it back every firing, but I don't see the need.

 

[madd0c]

Re: Full length sizing vs. neck sizing for accuracy

I have to disagree with Mark,
I definitely do NOT think neck sizing for accuracy is a "myth". As you say in your post, "If you have a good fit between your f/l die and your chamber" that right there demonstrates why neck sizing is superior.
Rounds neck sized fired in the same gun will be fit to THAT chamber very well.
This doesn't even begin to take into account that you can reload a neck sized case many more times than a f/l one because you are not working the bass on the whole case each time you size. Anneal necks every 3 to 5 firings, and as long as you aren;t using super max loads, your brass will last ALOT longer.

just my oppinion,
madd0c

 

[Powder_Burns]

Re: Full length sizing vs. neck sizing for accuracy

Chamber/neck/bullet/bore concentricity nuances aside, the advantages of neck sizing brass that is fireformed to your chamber are longer case life and a slight(marginal) increase in powder capacity. Neck sizing and loading your bullets further out of the case is a poor man's ackley improvement to maximize ballistic performance.

 

[MitchAlsup]

Re: Full length sizing vs. neck sizing for accuracy

One neck sizes to gain case life (3X-5X longer than FL sizing).

On FL sizes to put the case back to SAMMI specs. Such a case (when turned into a cartrige) will have optimal clearance in a precisely machined chamber, and self center better than a fire formed case.

Does it mater?

With a gun capable of shooting 0.35 MoA the NO sized ammo will loose something on the order of 0.02-0.05 MoA of accuracy. If this kind of accuracy is the difference between winning and loosing (and it is a HP matches) then FL sizing is the way to go.

If you just get jollies out of shooting, NO sizing has few detriments and lots of benefits.

 

[nhassey48]

Re: Full length sizing vs. neck sizing for accuracy

With my Remington SPS, the chamber is so huge it's like a 45-70 neck to a .22. So full length sizing would be alot of brass working each firing. If you don't want to buy a neck sizer, you could just bump the shoulder back .001 every time. That way it will still chamber fine, and you arn't working the brass as much. bump gauges are like $6 on sinclairs website. You CAN adjust a F/l die to just size the neck, but depending on your chamber, it will make it look all wierd.

 

[427Cobra]

Re: Full length sizing vs. neck sizing for accuracy

I FL everytime, I tried NS but didn't see any vast improvement in my shooting, having rounds that alway feed in more important to me than try to squeeze every last firing out of a piece of brass, invest in a headspace gauge to set up your FL die, and a decapping die, decapp the brass measure with the gauge, adjust your FL die so it reads .001-.0015 less, and use the instructions that came with your FL to wipe your ass, because that's all it's good for.

 

[Timo Turl]

Re: Full length sizing vs. neck sizing for accuracy

427Cobra, how many times do you think it possible to reload say Lapua brass if you FL evertime. Are we talking a massive difference than if you just NS ? Does this also mean you FL new brass too ?

 

[Swan]

Re: Full length sizing vs. neck sizing for accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TJ.</div><div class="ubbcode-body">427Cobra, how many times do you think it possible to reload say Lapua brass if you FL evertime. Are we talking a massive difference than if you just NS ? Does this also mean you FL new brass too ? </div></div>

It's really going to depend on what type (how hot) of load you are running with the brass. Could be 10 reloads, could be only 5-6. Never know until you try.

 

[Headgear]

Re: Full length sizing vs. neck sizing for accuracy

For what it's worth, one other side benefit of neck sizing is not having to use lube. It's just an unnecessary, sticky step and then you have to re-tumble them or wipe them off which is another waist of time.

 

[Timo Turl]

Re: Full length sizing vs. neck sizing for accuracy

i've got the Forster FL die. Should I neck size with this or get a dedicated NS die and if so which one for a 308 ?

 

[427Cobra]

Re: Full length sizing vs. neck sizing for accuracy

TJ I have some Lapua and Winchester brass with 20 reloads, but I also anneal, and used to tighten the primer pockets up with a RW Hart tool, now I just toss em

 

[Fuzzball]

Re: Full length sizing vs. neck sizing for accuracy

"instructions say you can screw the die out about 1/8" and it won't FL re size. does that mean it will just re size the neck and not, touch the shoulders?"

Well, you for sure won't touch the shoulders that way! But, that's really not the point of neck sizing; you don't want to squeeze the body at all because that forces the shoulder forward and that causes difficult chambering. Thus, how well you can do "neck sizing" with an FL die depends mostly on the cartridge and the differences between your rifle's chamber and the die's chamber; if the die hits the case walls you ain't just neck sizing!

It's not clear that accuracy is automatically better with either neck or FL sizing. As with most things about reloading, you must test your own rig to see what both methods can do for you.

Cases most often fail due to body or neck splits due to cold working the brass. Neck sizing MAY help with case life or it may not, depending again on your specific sizer die and chamber. A neck die that works the case a lot will split a neck faster than most FL dies will split the body. Lee's collet neck sizer works necks the absolute minimum and leaves perhaps the straightest necks, on average, of all neck dies.

proper neck annealing every 5-6 cycles will allow neck sized cases to last a very long time but it's also easy to damage necks with to much heat.

 

[Headgear]

Re: Full length sizing vs. neck sizing for accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I'm using a Forster Coax with the FL. sizing die the instructions say you can screw the die out about 1/8" and it won't FL re size.</div></div>


<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Lee's collet neck sizer works necks the absolute minimum and leaves perhaps the straightest necks, on average, of all neck dies. </div></div>

And they are dirt cheap. I have the same set-up as you and I got the Lee collet neck die and love it. I use it for about three to five reload cycles and when the cases start getting a little tight, I goop them up and run them through the FL die. If you can't find a Lee neck die for under $20.00, you're not trying! That will take the guess work out.

 

[Mr Flannel]

Re: Full length sizing vs. neck sizing for accuracy

I use a redding body die to bump the case shoulder about .0015" and then use a lee collet die - which is a fantastic piece of kit. This combo nixes the use of an expander ball and the collet die is lubeless - keeping mess and time expenditure down.

 

[Timo Turl]

Re: Full length sizing vs. neck sizing for accuracy

Thank you

 

[427Cobra]

Re: Full length sizing vs. neck sizing for accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Priest</div><div class="ubbcode-body">I use a redding body die to bump the case shoulder about .0015" and then use a lee collet die - which is a fantastic piece of kit. This combo nixes the use of an expander ball and the collet die is lubeless - keeping mess and time expenditure down. </div></div>

Thats twice the work, and IMHO the Lee Collet die overworks the shit out of brass, get a Redding Type S FL die and with the correct bushing the expander can be eliminated, and anytime two pieces of metal are moving against each other some sort of lube is required, period!

 

[Fuzzball]

Re: Full length sizing vs. neck sizing for accuracy

"anytime two pieces of metal are moving against each other some sort of lube is required, period!'

Correct. I even use a little lube with carbide handgun dies to reduce/prevent galling. But there is no material sliding/rubbing contact between the case and the die with Lee's collet system so lube has no benefit.

Lee's collet squeezes necks directly against a proper sized solid steel mandral and they can't possibly be reduced any further. How that "over works the shit out of brass" eludes me, IMHO.

The work of one additonal step to obtain the serious benfits of using a body die in conjunction with the collet neck die isn't excessive for many of us.

To each his own....

 

[vman]

Re: Full length sizing vs. neck sizing for accuracy

I have to agree with cobra on this one.

Aint nothin wrong with just setting up an FL sizing die to bump back the shoulder 0.001.

At the same time its also worthwhile in my opinion, to learn how to anneal. Dont forget, this skill can be applied to other things other than just the one type of case. You can use it to better preserve any ultra expensive or rare case types you own and also to aid in forming wildcat cases, such as the .338Edge.

Im willing to give neck bushing dies a go, but im not overly keen on spending a lot of money on the dies and multiple bushings and extra time researching.

 

[sobrbiker883]

Re: Full length sizing vs. neck sizing for accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">
Lee's collet squeezes necks directly against a proper sized solid steel mandrl and they can't possibly be reduced any further. How that "over works the shit out of brass" eludes me, </div></div>

the mandrel is undersized allowing the brass to be squished small then springback to final size. If you look closely you can see where the three slots between the collet fngers left the brass thicker.

I like the Lee neck sizer, but am not deluded that the brass isn't getting worked. You CANNOT size metal without it moving somehow-thats what sizing is. Any time it moves the molecular structure is shifted a bit (like bending a wire back and forth 'til it gets hot and breaks-this is the same in very slow motion, and the same goes for it expanding an d contracting in the chamber).

 

[Timo Turl]

Re: Full length sizing vs. neck sizing for accuracy

Assuming you just NS and don't bump the shoulder and if you are shooting a fast load, something like the 155 Scenar at 2950fps, how often are you finding a FL sizing is required ? I'm just trying to understand if a greater/faster load requires more frequent FL sizing. If it is every 2-3 loads it might as well be done each time ?

Also, has anyone got a link to a study/project showing the performance differential between FL & NS or seating depth. Lots of talk here about what each rifle prefers but just wondering if someone has some detailed examples using the same rifle with different combinations of brass prep and/or seating depth.

Thx

 

[Greg Langelius *]

Re: Full length sizing vs. neck sizing for accuracy

F/L sizing seems to be better associated with repeatable accuracy. Neck sizing seems to be better associated with longer case life. IMHO.

Greg

 

[Fuzzball]

Re: Full length sizing vs. neck sizing for accuracy

" just wondering if someone has some detailed examples using the same rifle with different combinations of brass prep and/or seating depth."

If they did (and many have) it would only apply to that rifle and load.

 

[Timo Turl]

Re: Full length sizing vs. neck sizing for accuracy

Yes I'm aware of that hence how i tried to word the q. Found this article/study on it which is quite interesting:

http://riflemansjournal.blogspot.com/2010/06/basics-resizing-case-dimension-changes.html

 

[ggmanning]

Re: Full length sizing vs. neck sizing for accuracy

I have always neck sized. I FL size every 5 loadings....nothing scientific and my brass would probably go longer before needing it. I am using Lapua brass and my loads are not super hot either. Lots of ways to skin a cat....

 

[ykrvak]

Re: Full length sizing vs. neck sizing for accuracy

Just a thought here guys. I'm not going to try and tell everyone that one way is better than the other because I certainly don't know it for a fact. However, If creating consistent uniform ammunition is what accuracy is based on then fl resizing every 4th or 5th reload is certainly not maintaining consistency. Will it negatively impact your shooting results? I don't know. I fL resize every time for that simple fact. I know it will chamber even when there is crude in my action and I'm not changing my case dimensions every few reloads. I work up my loads based on a FL resized piece of brass and that's how I shoot them. If I were looking for BR type accuracy I might feel very differently but I'm not. Again, just a thought.

 

[ggmanning]

Re: Full length sizing vs. neck sizing for accurac

I get no noticeable accuracy increase or decrease from FL vs NS for my puposes. I do it for brass life. The difference is more important for bench rest or professional paper punchers but if I work up a load that stays very accurate consistently I dont quibble over minor differences in my 100 yard groups. .25 is no better than .35 for how and what I shoot.

 

[Greg Langelius *]

Re: Full length sizing vs. neck sizing for accurac

The maxim is that when you change a reloading component, you've changed the load, and load tuning is in order. IMHO, that includes resizing methods.

 

[ggmanning]

Re: Full length sizing vs. neck sizing for accurac

I agree fully in some cases, but if the change makes no appreciable difference there is no need. I have not seen enough accuracy difference between FL and NS in my rifles to matter. That may not be the case for other rifles.....I can only comment on mine. If I saw any discernible difference I would modify my practices. I am sure that you, like me, have been doing this a long time and you keep what works and throw out what doesn't. In my shooting I have not seen enough difference so I follow my regimen above because it prolongs my brass life. If I saw a drop in accuracy I would FL only. I am sure just like you said that it changes the load but some changes make a big difference and some less. The last load I worked up shot less than .50 with NS, FLS,Neck turn and no neck turn. Since neck turning didn't appreciably help that load in that rifle I dropped it but I kept up then NS, FL routine because it shot great either way and the NS added brass life. Excuse my thinking out loud ramble Greg.....the point being introducing a variable does change a load but it may or may not make a difference in your end result. if it doesn't diminish your end result but offers a benefit, then it is a variable I keep.

 

[Headgear]

Re: Full length sizing vs. neck sizing for accurac

Neck or full length doesn't show a difference on my targets. if I use good dies, either shoots better than I do. For the time being I am neck sizing as much as I can to save on ware and tare of the cases.

 

[Mark Walker]

Re: Full length sizing vs. neck sizing for accurac

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">The maxim is that when you change a reloading component, you've changed the load, and load tuning is in order. IMHO, that includes resizing methods. </div></div>

Agree completely. If your process is that you NS until you have to FL, the case is different every single loading. Maybe only very slightly, but it can be enough to throw a load off a little (in particular when you are shooting at long ranges (1k or more).

Consistency is critical.

To my point about having good fitting dies, if you have good fitting f/l dies, you can f/l size every single time, bumping the shoulder back .001-.0015, and have very long case life as well.

It's no secret this is the way the Benchrest and F-Class crowd have gone. I know very few folks shooting either discipline that NS only any more...

 

[clay_breaker]

Re: Full length sizing vs. neck sizing for accurac

RE: "To my point about having good fitting dies, if you have good fitting f/l dies, you can f/l size every single time, bumping the shoulder back .001-.0015, and have very long case life as well.

It's no secret this is the way the Benchrest and F-Class crowd have gone. I know very few folks shooting either discipline that NS only any more..."


So how does one go about obtaining a "good fitting" FL die? I use Lee, and do both NS and FL sizing when needed, but I can see that the FL die is working the brass a lot more. Just wondering how you could get a FL die that was right for your chamber?

 

[Notso]

Re: Full length sizing vs. neck sizing for accurac

Ive tried both and see no appreciable difference on paper at 100 or on steel at 500+. Like others have said, I know FL every time specifically for the reliability of chambering. I recall once I went to the range and about 2/3 of my loads wouldn't chamber without hammering the bolt closed. So that sealed it for me.

Also, I tend to run hot loads - so I was having to FL every other or every 3rd time, so I went to FL because it wasn't really buying me anything.

One final thing - I disagree that FL "works the brass more". As long as you have the die set up correctly to just barely bump the shoulders back .002, I think it works the brass minimally compared to having to do a large FL size every 3-5 loads. I think a little at a time is better on brass than one big squeeze.

To claybreaker: read the reloading 101 thread for die set up instructions. It answers your question specifically.

 

[MitchAlsup]

Re: Full length sizing vs. neck sizing for accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TJ.</div><div class="ubbcode-body">Assuming you just NS and don't bump the shoulder and if you are shooting a fast load, something like the 155 Scenar at 2950fps, how often are you finding a FL sizing is required ? </div></div>

Starting with new Win cases and 47.8 gr Varget with 155 Scenars at 2950,

The number of reload cycles between a trip through the body die was: 6, 6, 5, 5, 4, 3, 3, <so far> (average across a lot of 100 cases)

The trip through the body die was determined with an RCBS case micrometer measuring the sholder position. More than 0.0017 long generated a trip through the body die.