6mm arc Staball Match Barnes 105 Match Burner

[Jason.N]

Staball Match powder round 2

In my first test of staball match i was less than impressed with the velocity accuracy and SD's. My first run was 26.5-27.5 grains. I was less than impressed.

This time i tested 27.5 up to 28 grains. The load data is limited. Hodgen shows 27 grains as the max load. So take my data with caution. There may be some hope for this powder after all.

Going up in charge weight proved to increase accuracy, velocity and smaller SD's. I never hit noticable pressure as the brass was clean and the primers showed no flattning or cratering. All kept their shape and look once fired.

2.26" COAL, Barnes 105 Match Burner, Rem 7 1-2 primer, Hornady 4x fired brass, Staball Match powder. 20" proof steel barrel, gas gun.

5 shot groups

27.5gr - 2503 fps 1.25" - SD 5 (10 shots)
27.8gr - 2538 fps .76" - SD 13 (10shots)
28.0gr - 2571 fps .6" - SD 5 (10shots)

 

[Lunchbag]

What are your normal low velocities look like with the 20-in barrel. I run a 26 inch barrel AR-15 and a 26-in barrel bolt gun. With 105 hybrids and Lever Revolution I get about 2780 out of the gas gun

 

[Rocketvapor]

The 6 ARC velocities listed on the Hodgdon site for SB 6.5 and SB Match show almost the same velocities ( 103, 107, and 110 bullets ).
Looks like compressed loads with SB 6.5 limit max loads before pressure.

Sort of odd when a round like the 22 Nosler shows a pretty drastic difference between the two.
I use the 90gr max load for 88's. and get close to 3000fps from a 28" barrel with SB 6.5 (fasted fps for all listed powders).
Listed max for SB Match is 150fps slower. About the same as IMR4350 that I have also used and get about 2850fps.