So I do not have a way to adjust primer seating depth at this point. I am using a RCBS hand priming tool and just seat by feel.
It could be the brass or flash hole, but I think its more related to the powder.
I did some testing with the same lot of brass and same lot of primers out of my old barrel, but using BL-C(2) and Hornady 75g OTM . While I definitely got some odd results on the high end, going lower provided better results than the actual black hills 77g OTM I tested in my gun for a base line.
Data from Hornadys 11th.
Hornady 75g OTM
Seated 2.250 per Hornady
LC brass
CCI 450 primers (same lot)
BL-C(2) powder
25.2, AVG 2652, SD 10.19, ES 35
25.4, AVG 2567, SD 13.79, ES 44
25.6, AVG 2589, SD 21.58, ES 75
25.8, AVG 2687, SD 28.67, ES 99
26.0, AVG 2710, SD 36.22, ES 117
Granted again this is some older data, I do believe I fired 10rnds per group on this one, but I may still have been at 12ft with the chrono, I can't remember. But I am doing better at keeping records going forward
.
In any case I will be testing this load again in the near future as well. Got overtime scheduled, i am really looking forward to having a chronograph again.