Lapua .308 Palma Brass
- Thread starter 762nato
- Start date
Some initial observations:
Virgin .308 Lapua Brass:
Weight 173.05 gr. spread over 10 cases 172.8-173.3
Capacity IMR 4895 51.9 gr. ( I know you are supposed to use water but I am not getting my equipment wet...)
Virgin . 308 Lapua Palma Brass:
Weight 172.05gr. spread over 10 cases 171.8-172.3
Capacity IMR 4895 50.9 gr.
Hoping to get out tomorrow with 556 nato, thay way I can run 2 chrony's in tandem, if they cooperate in the cold should have some data back to back with the same load in both cases out of my Coyote....
Should also thank Peter Dobson @ Hirsch Precision for bringing in the brass, nice to get cool new stuff to play with....
Andy
Virgin .308 Lapua Brass:
Weight 173.05 gr. spread over 10 cases 172.8-173.3
Capacity IMR 4895 51.9 gr. ( I know you are supposed to use water but I am not getting my equipment wet...)
Virgin . 308 Lapua Palma Brass:
Weight 172.05gr. spread over 10 cases 171.8-172.3
Capacity IMR 4895 50.9 gr.
Hoping to get out tomorrow with 556 nato, thay way I can run 2 chrony's in tandem, if they cooperate in the cold should have some data back to back with the same load in both cases out of my Coyote....
Should also thank Peter Dobson @ Hirsch Precision for bringing in the brass, nice to get cool new stuff to play with....
Andy
Well got out this afternoon:
Conditions -10 C, Wind 1/4 value @ roughly 7 oclock, partial cloud time 4 pm
Equipment: PGW Coyote, Nightforce 8-32 NS scope, Shooting chrony Beta Chrony.
Load: 40.0 IMR 4895 CCI Br4 Primer 178 gr. Amax @ .010" off the lands. All charges thrown on RCBS chargemaster, Forster Ulltra dies used for seating.
Well the chrony seemed to varry 30-40 fps weather the cloud was over the setting sun, or the sun was visable, also started to crap out on cold about 1/2 way through the 10 shot string with the regular brass.
Group size @ 200 with regular brass was 1.375". Group size with the Palma brass was considerably smaller but there where 3 high left flyers the furthest 1.25" from the center of the main group.
Chrony data as follows;
Palma Brass: Average velocity:2395
Exreme Spread 49
Standard Deviation 17.52
Far from stellar
Regular brass 8 shot string due to chrony malfunction
AV 2395
ES 75
SD 28.7
Also far from stellar.
I usually shoot lighter bullets but wanted to try some heavier ones so I tried to kill 2 stones with one bird. Normally I would use Varget or N-140 or RL15. I will have to several iterations of this test to try and develope sound data. ES was signifigantlly lower with the Palma brass, this should translate into better groupings.....
Conditions -10 C, Wind 1/4 value @ roughly 7 oclock, partial cloud time 4 pm
Equipment: PGW Coyote, Nightforce 8-32 NS scope, Shooting chrony Beta Chrony.
Load: 40.0 IMR 4895 CCI Br4 Primer 178 gr. Amax @ .010" off the lands. All charges thrown on RCBS chargemaster, Forster Ulltra dies used for seating.
Well the chrony seemed to varry 30-40 fps weather the cloud was over the setting sun, or the sun was visable, also started to crap out on cold about 1/2 way through the 10 shot string with the regular brass.
Group size @ 200 with regular brass was 1.375". Group size with the Palma brass was considerably smaller but there where 3 high left flyers the furthest 1.25" from the center of the main group.
Chrony data as follows;
Palma Brass: Average velocity:2395
Exreme Spread 49
Standard Deviation 17.52
Far from stellar
Regular brass 8 shot string due to chrony malfunction
AV 2395
ES 75
SD 28.7
Also far from stellar.
I usually shoot lighter bullets but wanted to try some heavier ones so I tried to kill 2 stones with one bird. Normally I would use Varget or N-140 or RL15. I will have to several iterations of this test to try and develope sound data. ES was signifigantlly lower with the Palma brass, this should translate into better groupings.....
Just messing around inmy loading room, flash holes in this brass are quite a bit smaller than the decapping pin in my Forster dies. Now I either blow out the flash hole so I can decap the brass or mess with the pin.....
I'm surprised no one commented on this yet...
When the palma brass came out I was intrigued, but nothing more. I couldn't see the reason to switch for small primers since they're already so hard to find.
With the info you've just given, I still do not see the point. Thank you for the clarification
When the palma brass came out I was intrigued, but nothing more. I couldn't see the reason to switch for small primers since they're already so hard to find.
With the info you've just given, I still do not see the point. Thank you for the clarification
Max Owner
CGN Ultra frequent flyer
I copied and pasted from Snipers Hide, the following spiels.......
The advantage using a small primer pocket verses a large pocket is to get a light ignition causing a more consistent burn and lowering the extreme spread. Years ago, RWS lg primers were the best primers for that application, but good luck trying to get your hands on them. And if you do, it'll cost you. Switching to a small primer in a 308 pretty much solve that problem
And another........
The reports from the Palma shooters who tested the brass indicated better velocity consistency - lower ES/SD. Also the small primer pockets give stronger case bases which handle the high pressure Palma loads better - less case expansion = more reloads before the primer pockets get too big.
The advantage using a small primer pocket verses a large pocket is to get a light ignition causing a more consistent burn and lowering the extreme spread. Years ago, RWS lg primers were the best primers for that application, but good luck trying to get your hands on them. And if you do, it'll cost you. Switching to a small primer in a 308 pretty much solve that problem
And another........
The reports from the Palma shooters who tested the brass indicated better velocity consistency - lower ES/SD. Also the small primer pockets give stronger case bases which handle the high pressure Palma loads better - less case expansion = more reloads before the primer pockets get too big.
