I have a mossberg mvp series 5.56 bolt action rifle. (It is 5.56 not .223). I’ve been shooting it for about 10 years now and it has a minimum of 3,000 rounds through it. I’ve always had to load it with a lighter than usual powder charge because it has a tendency to have primer cratering.
Recently I have revisited loading heavy for caliber bullets (69 - 73 gr bullets) with BL-C(2) powder. Max charge is 26 grains and I loaded down to 24 grains in 0.2 grain increments. I got the 73 gr bullets to go 2700 fps at 26 grains. It’s a 16” barrel.
I did 5 loads of each charge, every single one cratered the primer and all but the lightest load punched holes in 1-2 of the primers causing the firing pin to malfunction (pull the bolt apart and clear the primer obstruction and it’s good to go)
does my rifle just hate BL-C(2) or is it prone to pressure issues? I was using starline brass and CCI sr primers. I’ve read about carbon rings causing pressure signs but I clean very regularly with a bore guide.