Alpha Brass - .308 SRP

[Italianusmc_ny]

Evening all in Shooter Land,

Have a question out of curiosity.

Recently got my barreled action back from a very well known smith.
I supplied him with the Manson F/TR 2013 Team USA 308 reamer, my Hart Barrel and Action.

Since Lapua .308 Palma SRP brass is like finding Swiss Combat Medals at the moment in 500+ quantites, I purchased both Alpha and Peterson brass to test and use this season.

After my 1st firing of the Alpa Brass (Havent Tried the Peterson yet), the headspace measurement on the shoulder actually got squeezed a bit smaller by -.001.
Everything Chambered and fired like a dream for the 1st go around, resulting in .33", 5 shot groups at 100yds for velocity testing using N150 in .5 gr increments starting from 42.5 - 44grains and Berger 200.20x. Speeds were a bit slow averaging 2588fps with absoltley no pressure signs on the brass and ejecting like silk.
I will be going up in .5gr increments until I reach closer to 2680fps.

I havent had the time to 2nd fire the brass, but I have Cleaned, Annealed and F/L sized and bumped back -.002 and will see what measurements I get this weekend.

So I guess my question is..
Has anyone used a similar setup combination and seen a fired piece of brass actually go from 0 on the caliper before firing to -.001 after firing.

Im not concerned, its not like I got +.009 after firing.
Just curisoty to get a conversation going to compare notes.

 

[Straightshooter1]

Evening all in Shooter Land,

Have a question out of curiosity.

Recently got my barreled action back from a very well known smith.
I supplied him with the Manson F/TR 2013 Team USA 308 reamer, my Hart Barrel and Action.

Since Lapua .308 Palma SRP brass is like finding Swiss Combat Medals at the moment in 500+ quantites, I purchased both Alpha and Peterson brass to test and use this season.

After my 1st firing of the Alpa Brass (Havent Tried the Peterson yet), the headspace measurement on the shoulder actually got squeezed a bit smaller by -.001.
Everything Chambered and fired like a dream for the 1st go around, resulting in .33", 5 shot groups at 100yds for velocity testing using N150 in .5 gr increments starting from 42.5 - 44grains and Berger 200.20x. Speeds were a bit slow averaging 2588fps with absoltley no pressure signs on the brass and ejecting like silk.
I will be going up in .5gr increments until I reach closer to 2680fps.

I havent had the time to 2nd fire the brass, but I have Cleaned, Annealed and F/L sized and bumped back -.002 and will see what measurements I get this weekend.

So I guess my question is..
Has anyone used a similar setup combination and seen a fired piece of brass actually go from 0 on the caliper before firing to -.001 after firing.

Im not concerned, its not like I got +.009 after firing.
Just curisoty to get a conversation going to compare notes.

To gather some data for my new .308 Alpha brass, I loaded up ten to measure as virgin then to fire that I can measure the difference. I didn't load them to an extreme, but to a velocity (2710 fps for 168 SMK's) that my gun likes with the other brass. I had read an issues about pierced primers due to the larger flash holes that the Alpha brass has. And sure enough, three of the 10 cartridges resulted in my CCI 400's being pierced. But those piercings corresponded to those that had the highest velocity well over the intended 2,710 fps. . . like 2,740 - 2,755 fps. I was a little surprised by that as I backed off my typical load by .2 grs thinking case volumes would be less than my Lapua and Peterson brass . . . and it is, a little. For the larger charges, I believe I'll need to use something like CCI 450's that have thicker cups. . .???

Below are case measurements I took for comparison:

 

[X Count]

To gather some data for my new .308 Alpha brass, I loaded up ten to measure as virgin then to fire that I can measure the difference. I didn't load them to an extreme, but to a velocity (2710 fps for 168 SMK's) that my gun likes with the other brass. I had read an issues about pierced primers due to the larger flash holes that the Alpha brass has. And sure enough, three of the 10 cartridges resulted in my CCI 400's being pierced. But those piercings corresponded to those that had the highest velocity well over the intended 2,710 fps. . . like 2,740 - 2,755 fps. I was a little surprised by that as I backed off my typical load by .2 grs thinking case volumes would be less than my Lapua and Peterson brass . . . and it is, a little. For the larger charges, I believe I'll need to use something like CCI 450's that have thicker cups. . .???

Below are case measurements I took for comparison:

View attachment 1545744

I had heard the same thing re large flash holes in SRP brass but after testing with lapua vs alpha I never saw an issue. Yes I was using BR4s and 450S but I was also pushing a 208 at 2700+ out a 32" barrel with varget.

 

[KMart]

After my 1st firing of the Alpa Brass (Havent Tried the Peterson yet), the headspace measurement on the shoulder actually got squeezed a bit smaller by -.001.

Was this measurement taken just after firing or after resizing the once fired brass? I find it common, with new brass, for the shoulder to be a little shorter after firing virgin brass. This seems to be because the outside diameter grows to your chamber diameter resulting in the shoulder "backing up" a little.
After you squeeze the case down in a F/L die, the shoulder will move back forward.

 

[LVLAaron]

You need roughly .3-.5 less powder in the Alpha brass vs Lapua. I run BR or 450 primers... Never had a pierce or really even a flat primer with some really hot loads.

 

[9146gt]

Lapua 308 Winchester Palma Brass #4PH7226C

Product Information Cartridge: 308 Winchester Finish: Brass Condition: New Quantity: 100 Primed: No Primer Size: Small Primer Pocket *This is not loaded ammunition.

www.bluecollarreloading.com

Had plenty in stock when I was there today.
Tom