Load development with virgin brass?

[TheGerman]

Am getting into development for my 338 and it’s been literally forever since I’ve done this with a new caliber.

Got everything together and then it hit me; would things like ladder tests be skewed with virgin brass as the shoulder/headspace and neck tension would be ‘off’ from a fire formed round or would it not even matter?

I can see how it could and how it couldn’t.

 

[palmettoman]

Might as well get some data while you're fire-forming your first round of brass.

 

[Sheldon N]

Got everything together and then it hit me; would things like ladder tests be skewed with virgin brass as the shoulder/headspace and neck tension would be ‘off’ from a fire formed round or would it not even matter?

It matters. Did load dev with virgin brass in 7SAUM, had to partially redo on second firing since speed/pressure were different by almost a full grain in charge weight.

 

[BLKWLFK9]

Am getting into development for my 338 and it’s been literally forever since I’ve done this with a new caliber.

Got everything together and then it hit me; would things like ladder tests be skewed with virgin brass as the shoulder/headspace and neck tension would be ‘off’ from a fire formed round or would it not even matter?

I can see how it could and how it couldn’t.

I'm about to experience this with my 6BR. Did load dev with virgin lapua brass. My load should only get better numbers than before with better neck tension but might need to bump up a couple tenths of a grain.

 

[TheGerman]

It matters. Did load dev with virgin brass in 7SAUM, had to partially redo on second firing since speed/pressure were different by almost a full grain in charge weight.

This is what I was thinking between the neck, form firing the shoulder as well as just the overall bit that the brass gets worked from the first firing.

What had me think it wouldn't matter is, well, all factory brass (unless stated) is virgin brass isn't it? But then again, hows it compare to the 2nd loading/firing as well.

So yeah, I may just load up some to sight in and get initial data but then use the once fired to load the ladder test rounds with.

 

[T2hunter]

Did load dev on virgin brass when I first got my Lapua
Didn’t seem to matter to much
Have to start somewhere I’d say
Ended up going with 89.3gr retumbo
300gr smk @2720fps
Hope this helps

 

[Olen_4504]

from what i've gathered and my one time so far doing it. i doesn't hurt to do load dev on virgin brass.

just make sure to double check everything on your 1x fired and tweak as needed. it seems some people get lucky and don't need to change anything (like me) and some people do (Sheldon N)

 

[Danattherock]

Tight necks on Virgin brass are my main concern, I recently bought some mandrels just for that purpose. The variance in neck tension from virgin to fire formed is quite a bit more than I prefer.

 

[Holliday]

Tight necks on Virgin brass are my main concern, I recently bought some mandrels just for that purpose. The variance in neck tension from virgin to fire formed is quite a bit more than I prefer.

Same here. The alpha was running .003 so I ordered a mandrel.

 

[Danattherock]

I only use Alpha and Lapua and find both very tight from the factory. That's why I eventually broke down and got these mandrels.

 

[sjc929]

I don’t ever do load dev on virgin brass either. Odds are the geometry of the case will change enough to be significant. There are also other benefits. I can pick a random load based on looking at what others have reported as being successful, and get good precision. This means I can play around with a new barrel without worrying about being technical right away. It also means I never worry about barrels breaking in and speeding up, because that should happen while I’m still shooting my virgin fireforming loads if it is going to happen.

I also always run my virgin brass through an expander ball. Like others said, virgin brass usually has stupid tight necks. I always assumed they expected you to run the necks through something to remove any dings the neck received while still in the box, so they undersize them to assure even a small ding will be removed.

 

[Snuby642]

Am I the only one that fl sizes virgin brass so it is somewhat consistant with
previous brass. Most times it is small anyway but the necks have too many dings.

I thought this would at least get my neck tension in check?

 

[dirthead1]

Am I the only one that fl sizes virgin brass so it is somewhat consistant with
previous brass. Most times it is small anyway but the necks have too many dings.

I thought this would at least get my neck tension in check?

I do this as well with virgin brass.

 

[Holliday]

Am I the only one that fl sizes virgin brass so it is somewhat consistant with
previous brass. Most times it is small anyway but the necks have too many dings.

I thought this would at least get my neck tension in check?

I used to with Lapua because some of it would get banged up in the weekly UPS football game en route but I stopped with Alpha brass. That stuff shows up properly packaged and pristine. Now I am going to at least run a mandrel through the necks for less tension.

 

[sjc929]

@Snuby642 I don’t, just because I want to minimize the amount the brass stretches on the first firing. If I was trying to do load dev with virgin brass, I would definitely FL size it though.

A slightly interesting aside: I just got a prefit barrel from Proof for my AX, and it has the tightest chamber of any barrel I’ve ever had. The virgin brass is only growing .001” in headspace after being fired. About 5-10% of the cases give a tight bolt close, being slightly longer than most of the cases. I’ve never had virgin brass that was perfectly sized to a chamber before, an interesting coincidence.

 

[PBWalsh]

What are these mandrel things y’all speak of?

 

[T2hunter]

https://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/turning-expander-mandrels/generation-ii-expander-dies-prod38807.

 

[Holliday]

What are these mandrel things y’all speak of?

 

[spife7980]

What are these mandrel things y’all speak of?

http://www.accurateshooter.com/technical-articles/reloading/expander-mandrels-and-neck-tension/

 

[Snuby642]

@sjc929
I have the opposite, chambers on the large side / small brass.
Most of the time it's just the neck straitened and set.
Have yet to find a fit close.

Will check into Alpha brass.

With all the help from the hide my reloading has improved a lot.
Thanks to all !

 

[Holliday]

@sjc929
I have the opposite, chambers on the large side / small brass.
Most of the time it's just the neck straitened and set.
Have yet to find a fit close.

Will check into Alpha brass.

With all the help from the hide my reloading has improved a lot.
Thanks to all !

You will love the brass. I called and spoke with them at length before my purchase and they were extremely helpful. They even threw in a handwritten thank you card.

 

[redneckbmxer24]

Depending on how much the brass is growing it CAN shift your node once it’s fireformed. It doesn’t always though.

I do development and load up the batch. Once it’s all formed I’ll go back over just my node in .1gr increments again and go out of the node .3gr or so high and low just to see if anything shifted. I shoot them in a ladder over the chrono just like during development but just the short ladder to confirm. This method has always given me the data needed to go back and load it all up again.

 

[Snuby642]

Might as well get some data while you're fire-forming your first round of brass.

Emptying box ammo to reload gives you a baseline if similar bullet and the brass you really want.
If not does nothing for you.
If it's like 5.56 fine plink it but I think the big boy ammo would be a waste, especially if a veteran reloader. IMO

 

[supercorndogs]

@Snuby642 I don’t, just because I want to minimize the amount the brass stretches on the first firing. If I was trying to do load dev with virgin brass, I would definitely FL size it though.

A slightly interesting aside: I just got a prefit barrel from Proof for my AX, and it has the tightest chamber of any barrel I’ve ever had. The virgin brass is only growing .001” in headspace after being fired. About 5-10% of the cases give a tight bolt close, being slightly longer than most of the cases. I’ve never had virgin brass that was perfectly sized to a chamber before, an interesting coincidence.

I would send it in. That is way below sami spec for a chamber, if its hard chambering virgin brass.

I imagine with the case capacity you're are dealing with, you will find nodes that are 2 or 3 grains wide, that's my experience with the 300WM anyway. I have done load development with it in virgin brass, and didn't need to tweak when once fired came around. This is with a belted mag too, so the shoulder is about .012 out there on the first firing. Not something you should find in a conventionally head-spaced chamber.

 

[sjc929]

@supercorndogs I haven’t seen a need to send it in yet. It’s a 6.5x47L, so I never shoot any factory stuff, and am not worried about being able to run it (though I have a suspicion I would get some crazy good SD if I did run the factory stuff, they would probably have a perfect shoulder bump in this barrel). I happened to have a no-go gauge under my bench, and it behaved how I expected it too. The bolt will partially close on it, but stop around half way or so. I think the perfect fit is just a coincidence of having both a tight chamber and long brass. I still have another 150 rounds before I’ve shot all the virgin brass and will do my load dev. The only thing I’m really concerned about is being able to get my sizing die turned down far enough to get .002” bump, but I’ll cross that bridge when I get there, and I’m not convinced it will be a problem yet anyway. I’ll be interested to see if I notice the wide nodes you are talking about.

 

[supercorndogs]

@supercorndogs I haven’t seen a need to send it in yet. It’s a 6.5x47L, so I never shoot any factory stuff, and am not worried about being able to run it (though I have a suspicion I would get some crazy good SD if I did run the factory stuff, they would probably have a perfect shoulder bump in this barrel). I happened to have a no-go gauge under my bench, and it behaved how I expected it too. The bolt will partially close on it, but stop around half way or so. I think the perfect fit is just a coincidence of having both a tight chamber and long brass. I still have another 150 rounds before I’ve shot all the virgin brass and will do my load dev. The only thing I’m really concerned about is being able to get my sizing die turned down far enough to get .002” bump, but I’ll cross that bridge when I get there, and I’m not convinced it will be a problem yet anyway. I’ll be interested to see if I notice the wide nodes you are talking about.

The second half of that was directed at the thread. Your 6.5x47 has no where near the case capacity of the 300wm or 338 Lapua.

 

[Fig]

The biggest mistake that inexperienced people make is just flying into it. That can lead to bad experience. When it's virgin brass you need to go slow. You need to ease into it. Pumping the bolt as fast as you can won't be a good experience for one of you...

 

[Fig]

In all seriousness I do collect data, but not until it's fire-formed to the rifle on the second firing do I feel like I'm collecting data I want to apply as dope.

Some of the BR guys shoot a match while fireforming, but they're not shooting the parabolas at all different ranges like we are.

 

[MarinePMI]

@Snuby642
A slightly interesting aside: I just got a prefit barrel from Proof for my AX, and it has the tightest chamber of any barrel I’ve ever had. The virgin brass is only growing .001” in headspace after being fired. About 5-10% of the cases give a tight bolt close, being slightly longer than most of the cases. I’ve never had virgin brass that was perfectly sized to a chamber before, an interesting coincidence.

That was my experience as well with my last WinTac barrel; a pretty minimum spec chamber (a good thing).

 

[supercorndogs]

That was my experience as well with my last WinTac barrel; a pretty minimum spec chamber (a good thing).

Is that 6.5x47 also?

 

[FishDr]

@sjc929
If you are unable to get correct shoulder bump from the min spec chamber, here is what I did when I had a similar problem with a 270 rifle. You could get the Redding competition shell holders or just dedicate a regular shell holder to this set of dies. I did the latter and marked it. Then took fine grit polishing stone and removed the correct amount on top of the shell holder. It was about .0015 total as checked with a micrometer. Worked great. Perfect bump and easily repeatable.

 

[MarinePMI]

Is that 6.5x47 also?

Nope, 6.5CM. The original chamber spec was .004" over minimum for AI barrels. I think they cleaned that up and are closer to .001" now.

 

[Snuby642]

Have you had any problems from factory ammo @MarinePMI with the ai?

 

[MarinePMI]

Factory ammo? What's that?

Seriously though, I have never run factory ammo, so can't say that there is or is not an issue. I know a lot of other folks run factory ammo (some at our local club) and I've never heard of an issue.

 

[sjc929]

@FishDr thanks for the advice. I run a Co-ax press so unfortunately I can’t run the Redding shell holders. If I do run into a problem, my plan has been to either get a new set of the Forster shellholder plates and grind them down on top to allow the die to turn farther down, or just do the same to the bottom of the die.

 

[supercorndogs]

Nope, 6.5CM. The original chamber spec was .004" over minimum for AI barrels. I think they cleaned that up and are closer to .001" now.

.001 over minimum headspace and .001 over virgin brass is generally not the same. At least in my experience brass is .005 or more shorter than minimum headspace.

 

[TheGerman]

Seems its about 50/50 on doing development on virgin brass or not.

So for the guys that don't, WTF are you doing to get the brass once fired? I hate wasting rounds/componants on bullshit, but do you just sight the gun in and shoot all the brass once for the hell of it and then start the development?

 

[sjc929]

@TheGerman In my experience, .5 to .7 moa loads are extremely easy to get, and don’t require load dev to achieve if you’re using a quality barrel and action. If it’s for a caliber I’ve shot before, I’ll pick a load I used in the past to fireform. If not, I’ll look for something several other people have claimed to use successfully. For the Proof barrel I mentioned, I’m using a mild load I used a lot in my old barrel and am getting .3 to .5 moa consistently out of them with no load dev, which is about the same performance they gave in my old barrel with my old brass. These fire forming loads are more than good enough to do anything I want with them, so it’s not like I’m just blasting away components and barrel life for nothing. Once they’re all fireformed, I can do load dev to get the best velocity and SD that I can, but I’m not missing much performance until then.

 

[Snuby642]

Not me I do log tests with it.
I have found it will change next firing but can have it narrowed down.
I think on small cap rounds less and on large cap rounds more.

Probably someone knows a percentage to use for help.
I never checked back enough to have one since just starting to buy virgin brass

 

[MarinePMI]

@TheGerman In my experience, .5 to .7 moa loads are extremely easy to get, and don’t require load dev to achieve if you’re using a quality barrel and action. If it’s for a caliber I’ve shot before, I’ll pick a load I used in the past to fireform. If not, I’ll look for something several other people have claimed to use successfully. For the Proof barrel I mentioned, I’m using a mild load I used a lot in my old barrel and am getting .3 to .5 moa consistently out of them with no load dev, which is about the same performance they gave in my old barrel with my old brass. These fire forming loads are more than good enough to do anything I want with them, so it’s not like I’m just blasting away components and barrel life for nothing. Once they’re all fireformed, I can do load dev to get the best velocity and SD that I can, but I’m not missing much performance until then.

This. ^^^^

@TheGerman I think many over emphasize the fire forming aspect of virgin brass. While formed brass usually shoots a skosh better than virgin brass, for most quality barrels/chambers, the difference is lost in the noise IMO.

I just broke into a new lot of brass for my match rifle, and when checking zero and velocity, I was getting SD's at 2.9fps for five shots. Accuracy was fine (not super tight, but definitely 1/2 MOA). And this was with my go to 6.5CM load of 42.5grs of H4350. Same load I ran in the other lot of brass.

 

[T2hunter]

Seems its about 50/50 on doing development on virgin brass or not.

So for the guys that don't, WTF are you doing to get the brass once fired? I hate wasting rounds/componants on bullshit, but do you just sight the gun in and shoot all the brass once for the hell of it and then start the development?

Depends on how much brass you have, or how much you plan on shooting the gun I’d say.

On my 338L
I ran 100 cases thru the gun doing fire forming
First though,
All cases ran thru Sinclair carbide mandrel die
I Check with pin Hole gauges to inspect how tight the necks are and aim for (-.002 to caliber)
Chamfer inside primer pockets
Check brass length to reamer specs
Chamfer inside and outside of necks
Load up and go from here

My process is
All shots are done with a Lab/Radar and documented even with barrel break-in
Barrel break in 10-15 shots
Powder adjustments 25 shots
Bullet seating depth test 25 shots
300 yard powder adjustment 25 shots
(I’d of choose a longer range if I had a place to shoot out that far)
By doing this I was able to go thru what was the best and basically
Had all brass ready for fine tuning!

After all brass was now shot
Fine tune Powder, Primers, and bullet seating depth again now it’s done
Not saying it’s the right way! But it’s what works for me…

 

[Snuby642]

Am getting into development for my 338 and it’s been literally forever since I’ve done this with a new caliber.

Got everything together and then it hit me; would things like ladder tests be skewed with virgin brass as the shoulder/headspace and neck tension would be ‘off’ from a fire formed round or would it not even matter?

I can see how it could and how it couldn’t.

I think some of you have lost site of the main concern "NEW CALIBER " load development.
So no dope, no load recipe from experience on that round.

I would do normal development, record in stone my best round for future fire forming
virgin brass load them up and enjoy the rest.
That being said fire formed load will be different but numbers will only be off a persentage.

Chalk the first load up to finding a good fire forming load?

 

[Bradu]

Seems its about 50/50 on doing development on virgin brass or not.

So for the guys that don't, WTF are you doing to get the brass once fired? I hate wasting rounds/componants on bullshit, but do you just sight the gun in and shoot all the brass once for the hell of it and then start the development?

This is the reason I never understood why so many people complain about fireforming an Ackley improved cartridge when look at how many recommend doing it with virgin brass.

 

[spife7980]

Seems its about 50/50 on doing development on virgin brass or not.

So for the guys that don't, WTF are you doing to get the brass once fired? I hate wasting rounds/componants on bullshit, but do you just sight the gun in and shoot all the brass once for the hell of it and then start the development?

I dont think anyone is saying to not develop a good fireforming load, just that it wont be your last and finalized load. The brass will shoot different on the second firing 90% of the time.


I have 300 pieces of dasher to form for my upcoming build, Im going to find something that shoots well with the first 60 pieces (10 for initial sighting in and 50 of load development, 25 powder weight, 25 seating depth) and then load the remaining 240 to that "developed" load so that my first 300 rounds through the gun arent complete shit.

 

[sjc929]

I was down to my last 50 cases that I haven’t loaded yet, and I ran out of the 130 VLDs I was using. I decided to use these last ones to do load dev for the 140 Hybrids. Since these virgin cases are within .001” headspace of what they’ll be when I resize them, I’m just interested to see how much difference there is in basically the most ideal situation possible. The results gave a good illustration of my earlier point that .5 to .7 moa loads don’t require load dev to get when using a quality barrel and action.

That’s a 15 round group, where there was bad mirage for the last 10 shots, each shot was a .2gr increment in charge weight, and the velocity gap was 210 fps.

I also ran 10 rounds of the fire forming load I’ve been using over the Magnetospeed while I was out there.

I didn’t do any load dev for these at all, just picked a charge weight I knew was a commonly quoted node and loaded them. As you can see, they have the same ES and SD of what I would consider very good match factory ammo. This is why I typically don’t do load dev on virgin brass.

 

[supercorndogs]

Do you guys use dry neck lube? I was wondering about this after several different threads. One that seemed to show the carbon left in the neck is in fact not lubricous. That led to discussion off inside neck coatings. And to discussion that some necks like Lapua brass are clean from the factory, some are tumbled in wax, and others have their own inside neck coatings. It made me wonder if the need to change the load had more to do the the condition of the inside of the neck than anything else.

 

[Snuby642]

I tumble virgin brass in wax before loading, to make it the same as possible to the next loading.
The brass is cleaner the next time inside I have found.

Just what I have seen, no testing to confirm changes or not.
Clean and waxed is what I do but really can't justify the extra step with data.

 

[Sniper260]

If your developing a load, most times you also have a new barrel. 1 time have I found "THE LOAD" first shot, first try. Over the years Ive found most barrels Ive owned liked to just be shot first, which is a perfect time to fireform brass and just shoot. Put 20 or more rounds down the barrel, then .5 gr incriments, use this time to put bullets down the barrel, and narrow the search some.

I like a good 50 to 60 rounds down the pipe before I get serious. After that its nice to have a fire form barrel to fireform brass in. No need to wear a good barrel on new brass. Just me.