Load development on virgin brass

[JohnDeereGuy1996]

Finally got moved in to my new house and the last step of getting my gun room finished is setting up my reloading equipment. I’ve been out of the game for several years as far as reloading goes and have become more ocd. Have recently ordered some new equipment to reflect this over the crappy hornady kit I used to use.

Been doing tons of research on the latest and greatest equipment and it got me thinking that maybe my methods are out of date too.

I’ve always done load development with virgin brass and whatever powder charge produced the best results is what I ran with. Never ladder tested etc. I see varying opinions on this. Do you do load development on virgin brass? If not and you wait till you fire form all the brass what type of load do you do?(just seems wasteful)
Also should I run virgin brass through a full length size die or just carry on?

 

[JohnDeereGuy1996]

Follow up question. Let’s just say you start with 50 pieces and you went ahead and fire formed them all. Next up is load development. Do you load all 50 rounds to keep the number of firings the same? Also will it have any effect on the brass having different charge weights when you go to full length size for the second firing? As in can I get my die set and run through all 50 or will a case with a different charge measure different on the shoulder at times.

 

[hafejd30]

I run a mandrel through virgin brass necks. Then develop a load that shoots decent. Load up rest with that load. I’ll then do development on once fired brass after I have enough virgin stuff fired. Sometimes I’ll load test then shoot more virgin brass in the same session.

Generally I’ll cycle through the full 50 or whatever amount and keep same firings on them. That way if I loose the primer pockets or start splitting cases I’ll just toss them and start with new brass

Lee collet die is my preference. .0015 tension on the neck which is what I mandrel to as well. Usually virgin and once fired shoot relatively close to each other. I’ll body size in a separate step with Redding body die. Bump the shoulder .002”

Annealed every firing on my target loads. Every couple times on my hunting stuff.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

Fireform

Load develop



To keep all my brass on the same “firings” I use the second firing for load development. If I find a node before I’ve fired all brass 2x I just load the 1x to the load and run it all till 2x fired.

You got this. Nothing has changed.

 

[Rio Precision Gunworks]

Depends on your goals/use.

If it's a PRS rifle, you can do load development on virgin brass and things aren't going to change enough after firing to matter. I mostly just use virgin brass for everything and just sell the fired brass for 80% of the price new.

If you're looking for games where precision needs to be exploited to the max, you'll want to firearm and such before testing.


I only run virgin though sizer if the brass fits too tight in the chamber. This can happen when the reamer is saami minimum and brass is around saami maximum. Just size the body down and don't push the shoulders back.

 

[kilizyrag]

Oops wrong thread

 

[260shooter]

Follow up question. Let’s just say you start with 50 pieces and you went ahead and fire formed them all. Next up is load development. Do you load all 50 rounds to keep the number of firings the same? Also will it have any effect on the brass having different charge weights when you go to full length size for the second firing? As in can I get my die set and run through all 50 or will a case with a different charge measure different on the shoulder at times.

Different charge weights won't matter. All will have more than enough pressure to fireform the case. I would set my neck tension on virgin brass. Make a dummy round and measure the neck, minus .002-.003 for your bushing size. Use a expander mandrel on virgin brass then run them through your sizing die (remove the expander ball). Now you will have good neck tension on new brass.

 

[260shooter]

Depends on your goals/use.

If it's a PRS rifle, you can do load development on virgin brass and things aren't going to change enough after firing to matter. I mostly just use virgin brass for everything and just sell the fired brass for 80% of the price new.

If you're looking for games where precision needs to be exploited to the max, you'll want to firearm and such before testing.


I only run virgin though sizer if the brass fits too tight in the chamber. This can happen when the reamer is saami minimum and brass is around saami maximum. Just size the body down and don't push the shoulders back.

 

[JohnDeereGuy1996]

Different charge weights won't matter. All will have more than enough pressure to fireform the case. I would set my neck tension on virgin brass. Make a dummy round and measure the neck, minus .002-.003 for your bushing size. Use an expander mandrel on virgin brass then run them through your sizing die (remove the expander ball). Now you will have good neck tension on new brass.

I’ve never used a mandrel…as far as second firing goes what’s the process? If I wanted 2 thousandths neck neck tension I set my bushing to get it to 1 thousandths and then run a mandrel that’s 2 thousandths smaller then bullet diameter?

 

[ZA206]

I think it can be worthwhile to do load development on virgin brass assuming that you are setting the neck tension to the same as you would when normally resizing. I use Sinclair mandrels on all new brass. Seems like a waste of time and resources to just blast away for fire forming when you could use those resources to learn more about the virgin brass and once fired.

In fact, I'm currently working on comparing load developments with Virgin Hornady Large Primer 6.5CM brass and Peterson Small Primer 6.5CM brass vs. once fired. I resized the new brass and hit it with the mandrel for consistency. So far in my limited testing, Staball 6.5 is about 0.1 gr. less in the virgin resized Hornady and H4350 is about .2 gr less in the virgin resized Peterson vs. the once fired brass to get the same speeds. With Staball 6.5, once fired Norma brass takes about 0.5 gr more powder than resized virgin Hornady to get the same speeds, which is SIGNIFICANT!!!

This is all being done with a 24" Proof 6.5CM barreled AR10.

-ZA

 

[Rio Precision Gunworks]

I’ve never used a mandrel…as far as second firing goes what’s the process? If I wanted 2 thousandths neck neck tension I set my bushing to get it to 1 thousandths and then run a mandrel that’s 2 thousandths smaller then bullet diameter?

You'll pick a bushing that sizes the neck smaller than you want final inside diameter to be. Then you'll use the appropriate mandrel to expand the neck back out to final ID. Spring back and such will many times make the mandrel you use slightly larger than your desired inside diameter since things will spring back smaller because you're expanding. Where a bushing springs back wider because you're squeezing.

An example on a 6mm/.243 would be:

You have a desired ID of .241. The neck thickness is .013, so you double that for total of .026. Which means a loaded round is .269. You want that neck to be .267 OD to get a .241 ID. Normally, you'd use something like a .266 bushing.

Since using a mandrel, you'll just a .265 or .264 bushing. That will size the neck smaller than your desired final ID/OD.

Then you'll use something like a .242 or .2415 (sometimes a .241) mandrel to expend the neck back up to final size.

 

[Rio Precision Gunworks]

You can also use a non bushing die. That will size the neck much smaller than the size of the mandrel. Which means you'll have more resistance to the mandrel as well as more spring back.

You won't have much extra work hardening (that's just dogma perpetuated) as sizing and such does very, very little work hardening. Almost all of the hardening is done when the round is fired.

But, you'll find that you will need more lube and a larger mandrel to consistently mandrel up from a smaller non bushing die.

 

[FredHammer]

You can also use a non bushing die. That will size the neck much smaller than the size of the mandrel. Which means you'll have more resistance to the mandrel as well as more spring back.

You won't have much extra work hardening (that's just dogma perpetuated) as sizing and such does very, very little work hardening. Almost all of the hardening is done when the round is fired.

But, you'll find that you will need more lube and a larger mandrel to consistently mandrel up from a smaller non bushing die.

This is all I do. Bushing dies scare me! As you mentioned I have to size with a larger sized mandrel to hit the .0015 spring back size. If one knows that, then all good in the hood!

 

[Rio Precision Gunworks]

This is all I do. Bushing dies scare me! As you mentioned I have to size with a larger sized mandrel to hit the .0015 spring back size. If one knows that, then all good in the hood!

The Area419 dies don't use a bushing. Just have different mandrel sizes. Just getting ours set up, so not sure how I like them yet.

I've used both bushing and non in the past. Not sure which one I like better. Bushing in convenient to set up where the mandrel is only expanding .001 or so and easier on the arm pulling the handle.

 

[FredHammer]

The Area419 dies don't use a bushing. Just have different mandrel sizes. Just getting ours set up, so not sure how I like them yet.

I've used both bushing and non in the past. Not sure which one I like better. Bushing in convenient to set up where the mandrel is only expanding .001 or so and easier on the arm pulling the handle.

I'm biased here, so I vote mandrel! I've also noticed running the brass through the FL sizer with expander removed and bringing back to caliber size by .006-008 makes the dimensions hold better. Just tickling a couple thou didn't seem to be as effective.

 

[diggler1833]

I always run virgin brass through an expander mandrel, or at least over the expander ball of a F/L die. Sometimes case mouths can get dented slightly in packing or shipping. It doesn't take any time at all to ensure your neck tension is relatively consistent either.

I also do load development with virgin brass. Some may poo-poo on that idea, but I've found that it gets you 98% of where you'll end up. My last two 6.5x47s actually prefer the exact same load on fireformed brass that they did when they were new...even though the datum point on the shoulder was .003 shorter with virgin brass (.005 off from the factory, and I bump .002 when resizing). You can still figure out what bullet/powder combos your rifle likes on virgin cases...just understand that you may have to tweak your charge weight a touch after you've fireformed.

 

[FredHammer]

I always run virgin brass through an expander mandrel, or at least over the expander ball of a F/L die. Sometimes case mouths can get dented slightly in packing or shipping. It doesn't take any time at all to ensure your neck tension is relatively consistent either.

I also do load development with virgin brass. Some may poo-poo on that idea, but I've found that it gets you 98% of where you'll end up. My last two 6.5x47s actually prefer the exact same load on fireformed brass that they did when they were new...even though the datum point on the shoulder was .003 shorter with virgin brass (.005 off from the factory, and I bump .002 when resizing). You can still figure out what bullet/powder combos your rifle likes on virgin cases...just understand that you may have to tweak your charge weight a touch after you've fireformed.

My experience is the same as yours. I will buy brass 100-250 count and for a while I run the load developed recipe till they are all fired. Many times I see no difference in the second firing, hopefully just a slight reduction in pressure.

 

[Rio Precision Gunworks]

Here is small example.

Left ammo: 6gt Alpha brass. Pulled straight out the box. Primed, chamfer, powder, seat 109 Berger.

Right ammo: once fired alpha from above. Case shoulder moved forward .005”. Bumped .001 in area 419 die with .241 mandrel. Prime, chamfer, powder, seat.


So, for 6gt PRS ammo, I don’t care. This load isn’t even “worked up” for the barrel. Just loaded to speed I want and .030 off lands in fresh chamber.

Other cartridges and/or different uses may vary.

 

[JohnDeereGuy1996]

You'll pick a bushing that sizes the neck smaller than you want final inside diameter to be. Then you'll use the appropriate mandrel to expand the neck back out to final ID. Spring back and such will many times make the mandrel you use slightly larger than your desired inside diameter since things will spring back smaller because you're expanding. Where a bushing springs back wider because you're squeezing.

An example on a 6mm/.243 would be:

You have a desired ID of .241. The neck thickness is .013, so you double that for total of .026. Which means a loaded round is .269. You want that neck to be .267 OD to get a .241 ID. Normally, you'd use something like a .266 bushing.

Since using a mandrel, you'll just a .265 or .264 bushing. That will size the neck smaller than your desired final ID/OD.

Then you'll use something like a .242 or .2415 (sometimes a .241) mandrel to expend the neck back up to final size.

Okay I believe I’m following. Then I suppose full length size with the expander taken out?

 

[JohnDeereGuy1996]

Really appreciate all the info fellas!

 

[JohnDeereGuy1996]

You can also use a non bushing die. That will size the neck much smaller than the size of the mandrel. Which means you'll have more resistance to the mandrel as well as more spring back.

You won't have much extra work hardening (that's just dogma perpetuated) as sizing and such does very, very little work hardening. Almost all of the hardening is done when the round is fired.

But, you'll find that you will need more lube and a larger mandrel to consistently mandrel up from a smaller non bushing die.

This seems like the easiest route to take. Any recommendations on what dies to get? I used to run just lee or rcbs but looking to get past that and buy some quality dies.

 

[Rocketmandb]

Okay I believe I’m following. Then I suppose full length size with the expander taken out?

Yes, take the expander ball out. For me, I like to select a mandrel size that corresponds to the neck tension I'm looking for, then use the bushing that minimally engages the sized brass. The more you size down the neck (and thus, the more the mandrel sizes it back up), the more variability gets introduced and the more you work the brass.

I did a post a while back showing the impact of mandrel (or not) and neck lube (or not):

Mandrel Musings

When I first got my K&M arbor press for seating, I was somewhat surprised at the spread of the values of force required to seat bullets. Knowing that neck tension plays a significant role in ES/SD, I started doing various things to try to bring seating force in line. I had been doing most my...

www.snipershide.com

 

[R_A_W]

Load development... If it's a new barrel, I won't even begin load development until I have ~200rds on the barrel. I do a charge weight ladder to get an idea of where pressure develops & then just use a safe charge weight & SMKs to practice positional shooting for the rest of those ~200rds. After that, I pick a charge weight somewhere >1gr below where slight pressure signs show w/ an expected velocity I deem acceptable. I start w/ a seating depth that has worked for others for a specific bullet & might play around with seating depths, if need be. If velocity was disappointing, I guess I might revisit charge weights, but I haven't had that happen yet.

Brass... I do process new brass by sizing the neck - first with a bushing if I determine it's necessary & then always expand with a mandrel. I do load development w/ unfired & fired brass, it just depends on the cartridge & where I'm at in my brass supply. I'm careful to keep the firing count consistent across the life of the brass. I once lost track on one lot of RP brass and ended up w/ 5-10 firings. Some of the primer pockets were very loose and I started getting a lot of flyers. I don't know if it was neck tension or ignition issues (likely both), but I just discarded the whole lot & replaced. Flyers went away.

Dies... I recommend LE Wilson FL Sizer w/ Bushing, Whidden or Redding TiN bushings. I like Porter's Precision Products' mandrel, but 21st Century and LE Wilson will also be quality. There are also fancier dies out there, like Micron Precision.

Your OCD will help you out. Once you have a very consistent process, you will be able to locate & correct issues much more rapidly. Familiarity with a specific cartridge & your tools will also speed up issue resolution.

 

[Malum Prohibitum]

6gt Alpha brass. Pulled straight out the box. Primed, chamfer, powder, seat 109 Berger.

Just so I am clear, no mandrel, no neck resizing bushing or full length die resize of any kind. Just a VLD chamfer, and seat the bullet?

Please assume I am stupid when you answer because I will take your answer literally. I am just about to start with handloading 6 GT with virgin Alpha brass, and that is what I was considering doing (if FedEx delivers my little RCBS VLD chamfer tool today like is predicted on the Track My Shipment), so I am ok doing no other brass prep, just chamfer?

Right ammo: once fired alpha from above. Case shoulder moved forward .005”. Bumped .001 in area 419 die with .241 mandrel. Prime, chamfer, powder, seat.


So, for 6gt PRS ammo, I don’t care. This load isn’t even “worked up” for the barrel. Just loaded to speed I want and .030 off lands in fresh chamber.

Other cartridges and/or different uses may vary.


View attachment 8290158

I bought the Hornady overall length gauge and the modified 6 GT case sold by GA Precision. I am still going to need to watch some YouTube videos of how to figure out .030 off the lands.

I will be using 107 Sierra Match Kings, Varget, and CCI 450 primers. Anything you have to add about powder charge and such would be welcome.

 

[Darkside-Six]

I do load development on virgin brass. Just need to make sure my barrel as 100 rounds at least down it so it’s sped up. I run them over a neck mandrel to make sure they’re all uniform but aside from that I just load and shoot. Never seen any difference. I is r worry about fire forming as I’d rather save the barrel life. I try to buy larger batches of brass. 500-600 pieces at a time so I can run a match or two without having to re-prep brass but I also anneal and do the same thing every time I reload with the same steps so if some of them get few more firings on them then others it doesn’t really effect anything.

 

[Malum Prohibitum]

I do load development on virgin brass. Just need to make sure my barrel as 100 rounds at least down it so it’s sped up. I run them over a neck mandrel to make sure they’re all uniform but aside from that I just load and shoot. Never seen any difference. I is r worry about fire forming as I’d rather save the barrel life. I try to buy larger batches of brass. 500-600 pieces at a time so I can run a match or two without having to re-prep brass but I also anneal and do the same thing every time I reload with the same steps so if some of them get few more firings on them then others it doesn’t really effect anything.

I bought 500, so, yeah, I really do not want to go shoot them all first, 500 bullets and primers and powder, just so I can reload them as once fired!

Besides, if I can obtain a result like Rio Precision Gunworks did, it would be good enough using virgin brass to run in PRS type competition.

 

[Rio Precision Gunworks]

Just so I am clear, no mandrel, no neck resizing bushing or full length die resize of any kind. Just a VLD chamfer, and seat the bullet?

Please assume I am stupid when you answer because I will take your answer literally. I am just about to start with handloading 6 GT with virgin Alpha brass, and that is what I was considering doing (if FedEx delivers my little RCBS VLD chamfer tool today like is predicted on the Track My Shipment), so I am ok doing no other brass prep, just chamfer?




I bought the Hornady overall length gauge and the modified 6 GT case sold by GA Precision. I am still going to need to watch some YouTube videos of how to figure out .030 off the lands.

I will be using 107 Sierra Match Kings, Varget, and CCI 450 primers. Anything you have to add about powder charge and such would be welcome.

I'd have to check notes, but I'm usually pretty detailed with posts. So, if I didn't post that I used a mandrel, it's very likely I did not. And yes, when I'm not looking to go overboard on prep and stuff, just a hand VLD chamfer tool before dumping powder. Maybe two twists on the chamfer tool.

I would suggest using some sort of neck lube though. I use Neolube on everything. Virgin brass can sometimes come overly clean and the seating force is very high just due to friction and not necessarily the inside diameter of the neck.


Also, I'd highly, highly recommend Berger bullets. They really do make things much easier.

 

[diggler1833]

I absolutely do load development on virgin brass. I do however at least run the cases over an expander mandrel or at least an expander ball from a F/L sizing die (backed out). I then chamfer and debut, but that's it.

Even with Lapua, Alpha, and Peterson, I will find a few pieces that run easier/harder over the mandrel than the others. Not only does it remove any potential dings in the case mouth, but it also uniforms the friction interference...plus it only takes about 5 minutes per 50 cases.

I just started load development on my new 6CM barrel for my AT-X this afternoon. Velocities are low, so I'll have to step it up a bit. I'm not liking the SD and ES on the higher charge today either. Barrels are individuals. I do expect it to speed up a bit, but if I'm not over 2,950 I might as well be shooting my GT. 108gr ELD-M in *virgin* Peterson brass and H4350.

 

[Malum Prohibitum]

I absolutely do load development on virgin brass. I do however at least run the cases over an expander mandrel or at least an expander ball from a F/L sizing die (backed out). I then chamfer and debut, but that's it.

Even with Lapua, Alpha, and Peterson, I will find a few pieces that run easier/harder over the mandrel than the others. Not only does it remove any potential dings in the case mouth, but it also uniforms the friction interference...plus it only takes about 5 minutes per 50 cases.

I just started load development on my new 6CM barrel for my AT-X this afternoon. Velocities are low, so I'll have to step it up a bit. I'm not liking the SD and ES on the higher charge today either. Barrels are individuals. I do expect it to speed up a bit, but if I'm not over 2,950 I might as well be shooting my GT. 108gr ELD-M in *virgin* Peterson brass and H4350.

View attachment 8369038
View attachment 8369039

What size mandrel do you use? I was considering 0.2400" or 0.2405" from 21st Century

 

[diggler1833]

What size mandrel do you use? I was considering 0.2400" or 0.2405" from 21st Century

So, please understand that some guys will "poo-poo" me for saying this...but on bolt guns I run .002 under on everything, and I haven’t been disappointed yet.

My 21st Century die currently has a .241 mandrel in it for my .243 stuff.

 

[Malum Prohibitum]

Why poo-poo? Not enough neck tension? Too much?

 

[hafejd30]

So, please understand that some guys will "poo-poo" me for saying this...but on bolt guns I run .002 under on everything, and I haven’t been disappointed yet.

My 21st Century die currently has a .241 mandrel in it for my .243 stuff.

I wouldn’t poo poo. For a bolt gun .0015 is my goal

 

[diggler1833]

Why poo-poo? Not enough neck tension? Too much?

Friction interference is a variable that can and will have an affect on accuracy. Some barrels will like more than .002, some less. How much effect? Less in my experience than other variables (powder charge, seating depth) but consistency in that friction interference certainly helps. Some guys do great with just bushing dies. In the end the target is what determines what is needed.

For me, that .002 is a happy spot that just seems to perform well across everything. But a decade + ago I just used whatever the expander ball was in my full length dies, and I recollect having some pretty accurate rifles back then too.

 

[Malum Prohibitum]

So I should not be worried about whether .002 is sufficient to keep the bullet in place and not affect concentricity or anything else when under the clock and jamming that bolt forward to chamber for the next shot? That is the main reason I had been considering .003 or .0025 (.240 and/or .2405).

You two are running .002 and even .0015.

 

[diggler1833]

So I should not be worried about whether .002 is sufficient to keep the bullet in place and not affect concentricity or anything else when under the clock and jamming that bolt forward to chamber for the next shot? That is the main reason I had been considering .003 or .0025 (.240 and/or .2405).

You two are running .002 and even .0015.

.0015 is definitely sufficient to keep that bullet in the case. Maybe you'd have issues in an African Plains rifle or chambering and ejecting the same round in a semi auto a half dozen times...but I'm just spitballing and have never conducted a setback test under those conditions (I still lightly crimp my AR ammo). In your standard bolt gun or 26lb Pee Arr Ess 6mm rifle you'll be 100% fine.

No reason why you can't try .003 though man. It might work great for you. Only one way to find out.

 

[hafejd30]

So I should not be worried about whether .002 is sufficient to keep the bullet in place and not affect concentricity or anything else when under the clock and jamming that bolt forward to chamber for the next shot? That is the main reason I had been considering .003 or .0025 (.240 and/or .2405).

You two are running .002 and even .0015.

I’ve never had an issue. I wouldn’t run the same tension in a semi auto. I’ve even tested sending the bolt home fast as possible on a round several times to see if I could get it to move and could not. Even when I pull bullets with my hammer style puller it takes a couple wacks. I’m not running anything with massive recoil either

You can run more and have just as good of accuracy. .003-.004 isn’t a ton and may shoot just as well. My best ammo and consistency has come from .0015-.002 tension. I know guys using rcbs dies which are probably.004-.005 and also guys who soft seat bullets. Depending on use and overall goals will dictate what methods you can or will pursue

 

[TheOfficeT-Rex]

I've played with mandrel size and pin gages. IME, brass tends to pin 1-2 thou smaller than the mandrel. I generally run a mandrel 1 thou smaller than bullet size for about .0015" interference fit. I don't anneal, and it will pin differently virgin vs 12 times fired. Except at the extremes, I don't notice much effect on target, and a larger mandrel makes downstream steps of trim & seat a little smoother.

Again IME, I haven't seen bullet setback in my AR-15 or bolt gun, even when it pins only 1k under. I have seen a 50 beo setback bullets with poor crimp, but there's a difference between a 500gr bullet from a 7 pound rifle and a 110gr bullet from a 19 pound rifle. If you're smashing the tip when feeding from the mag, I'd be looking at fixes other than ammo.