Virgin brass vs. once fired.

[Laguna Freak]

Please excuse my ignorance, but I'm trying to learn.
What is BtS?

Case "Base to Shoulder". You'll need a comparator to measure it on a fired case. It will usually measure within a couple thou of your actual chamber dimension. If the bolt is stiff to close on that case, its safe to assume it is an exact fit and you need to bump the shoulder back a couple thou when sizing.

 

[MtPockets]

Case "Base to Shoulder". You'll need a comparator to measure it on a fired case. It will usually measure within a couple thou of your actual chamber dimension. If the bolt is stiff to close on that case, its safe to assume it is an exact fit and you need to bump the shoulder back a couple thou when sizing.

Thank you!

 

[44-40]

I use virgin brass in 6 dasher load development , high pressure loads first time ... I never anneal once fired brass. Virgin brass is already soft, it takes quite a few cycles to harden it up, if it's not overworked. I ran Lapua 308 cases 40 times and never annealed them, with excellent accuracy.
Just loaded some 30 RAR reformed from 450 Bushmaster, that were once fired. I annealed those 80 cases, after going from 45 to 30 caliber also requires a slight neck turning. These reformed cases were very accurate in an AR 15, with a repurposed Rem 700 barrel with 8000 rds on it, cut out most of the firecracking and chamber an old 308 to 30 Rem AR. So I only do what's necessary to achieve the results I want. Once fired and new brass are treated the same load and shoot. There was a difference in primer size and consistency in grouping and velocity, with Palma & regular LR Lapua cases, the LR primer cases were better than Palma cases with the powder and date tested...the best cases for the smallest groups was the new hybrid SS head cases, reformed to 308, beat Lapua...in a one day test.

 

[ButterBean]

3X fired before you get settled brass

 

[Rosebud]

3X fired before you get settled brass

Mr. Bean, do you know of a way to test where brass becomes so brittle it must be annealed? I've heard some say that that they go many,many firings without annealing. Others after each firing. Your thoughts?

 

[ButterBean]

Mr. Bean, do you know of a way to test where brass becomes so brittle it must be annealed? I've heard some say that that they go many,many firings without annealing. Others after each firing. Your thoughts?

Bud the machine to test hardness is expensive my suggestion is to just set a sequence, once every 2 firirings or what ever feels good to you, just make it routine just like everything else we do

 

[ButterBean]

Now with that being said you can feel excessively hardened brass with you fingers

 

[Rosebud]

Now with that being said you can feel excessively hardened brass with you fingers

Pretty much what I've been doing for a long time, just never heard of a testing machine. Thanks for the info.

 

[ButterBean]

Pretty much what I've been doing for a long time, just never heard of a testing machine. Thanks for the info.

Vickers hardness tester

 

[Laguna Freak]

Thank you!

You're welcome

 

[VarmintBob]

When brass is new, it is smaller than it will ever be after you fire it. If you have a large chamber the brass has to stretch quite a bit to swell up to fit that chamber when you fire it. Some of the energy of the shot is used to do this brass stretching. So that energy is not available to propel the bullet. Once the brass has had this initial stretch, subsequent firings have more energy to propel the bullet if you continue to use the same powder load. If you want the load to shoot the same as it did originally, reduce the powder load till you get back to that original muzzle velocity. It's almost rocket science but not quite.

 

[Barrelnut]

Just did some shooting a few days ago with new brass vs 1x fired in a 300 RUM. Same load and bullet in 1x fired brass was 24 FPS faster.

 

[emp1953]

Curious, who cleans and FLS virgin brass before loading?

Me

 

[Laguna Freak]

Me

Full length sizing here. I've learned to harbor a general low level distrust for mfr's.