Allen in MT
Member
Just got a 100 count box of Alpha 6mm CM SPR. Looks good so I loaded 5 with the same load I had in my Hornady LRP brass which was 39.8 grains of H4350 Took them to the range to fire them and ended up with a tight extraction. bolt lifted up ok but couldn't pull bolt back, had to beat it back with palm of my hand so I shot a second, same thing. Got to looking at primer an it looks like they are cratered.
Got back to the bench and de primed and weighed the empty case's and then weighed the Hornady cases. The Alpha brass weighed right at 10 grains heavier than the Hornady cases. Weighing 3 case's of each the Hornady weighed Ave 148.7gn and the Alpha was 158.9gn avg, so that is telling me less case capacity, got to start with a lower powder charge.
If you have 6mm cm Lapua cases can you get a avg weight of 3 cases without primers and the same if you have Peterson 6mm cm cases.
Got back to the bench and de primed and weighed the empty case's and then weighed the Hornady cases. The Alpha brass weighed right at 10 grains heavier than the Hornady cases. Weighing 3 case's of each the Hornady weighed Ave 148.7gn and the Alpha was 158.9gn avg, so that is telling me less case capacity, got to start with a lower powder charge.
If you have 6mm cm Lapua cases can you get a avg weight of 3 cases without primers and the same if you have Peterson 6mm cm cases.