5.56 chamber 16" 1/7 BBL
LC 1x fired brass, CCI 450 SRM primer
2.260 COAL, no crimp
I've so far loaded some test rounds with the 77tmk starting at 22.3gr of 8208. Up to 23.1 in .2gr increments. 22.3, 22.5, 22.7 all shot well, and the group was all really tight across that powder range. Really just one sub 1" group. Once I got to 22.9 and 23.1 the group opened up. I still don't see pressure signs. In your guys opinion, should I back down and just load at 22.5gr or keep going up and see if the group comes back together? I know I need the speed to keep the bullet doing its job. Realistically I'm not shooting a deer with this past 300, and that would be a stretch for where I hunt with a rifle here.