6.5X47 Lapua Vs Peterson Case Capacity

[Superjet]

Has anyone compared the case capacity between 6.5x47 Lapua Brass and 6.5x47 Peterson brass? I know that Peterson dasher is less than FF Lapua, was curious if the 47 is that same.

 

[acronut]

Anyone??

 

[diggler1833]

Anyone??

I've got a sample size of 20 cases of H2O capacity done for Lapua in that cartridge...so if someone has the Peterson brass for me to borrow for a firing we can at least get a general idea .

 

[ImperfectLiberty]

I have some 3x fired Peterson and some 4x fired Lapua brass I can get some capacities on over the next couple nights. I know that the Peterson is definitely a lower capacity case because it takes less powder to reach the same velocity. I'll see what they average out to and report back by Sunday hopefully. They're all fired in the same chamber and mostly the same loads so it should be a good comparison.

 

[ImperfectLiberty]

TL;DR: Lapua averaged 45.815gr, Peterson averaged 45.615gr, with the Peterson being more consistently uniform.

Case capacities-
6.5 x 47 LAPUA -all fired in same rifle / chamber w/ same loads

LAPUA IS 3x Fired
Peterson is 4x Fired

Measured on 2 chargemaster Lights warm and calibrated
using 50/50 mix of water and 91%. Isopropyl alcohol.

Measured round robin style so I didn't know what case I was measuring.

The Lapua cases averaged 45.815gr with an SD of 0.07647gr

The Peterson cases averaged 45.615gr with an SD of 0.05871


This is right in line with my experience with Peterson VS Lapua. I have done these tests with 300 Win Mag, 260 Rem, 6.5 Creed and 308 and it's always between .2 and .3 gr smaller capacity for the Peterson. In my limited sample sizes it has also held true that the SD is smaller with the Peterson. Not by much, but they do seem to be more uniform. Hopefully this helps a little. Nothing crazy scientific but I'd like to contribute where I can!