My DPMS LR308 (24in SS barrel) has point of impact change by 2-3 inches every 2-3 shots. I start out with 6 shots of cheap non-match ammo as a warm-up and to foul barrel after cleaning.
When I start using the match ammo, I will get 2 shots at one point, right next to each other, centers 1/3 of an inch apart. Then the next two will hit 2-3 inches away from that, also right next to each other. And the next two will hit somewhere else near each other. Its not linear either. Sometimes the point of impact will move up right, sometimes it will move left, sometimes down left.
It seems my rifle holds point of impact for 2 shots and then goes way off. But with cheap ammo it maintains 1.00 to 1.25 inch groups with almost no fliers.
Does my rifle hate the match ammo, or am I doing something wrong? I usually take 40 seconds between shots to let the barrel cool off, and I do 6 shots (3 shots per target) before waiting for ceasefire to switch out targets. Has this happened to anyone else? The point of impact change is very significant.
I use Black Hills 168g BTHP for my "match" ammo. I've seen it do consistant 1/3 groups out of a good bolt-action. My "cheap" ammo is SSA 168g BTHP. So ammo is almost identical, the Black Hills is higher quality.
