My Krieger 4 groove and Harts shoot very tiny groups with a chamber with very little freebore plus a tad of throat where the 169g Sierra sits .020 above the shoulder/Neck junction. 1" groups at 300 are not unusual, but I like #5 contour to Max Heavy Varmint with Gentry muzzle breaks. One 10T Krieger shoots in the 2's at 200 yards with 175g Sierra tmk with 42g of 8208.
OP, I would do a weight calculation on a 20", #5 contour, then a #4.
OP, I would do a weight calculation on a 20", #5 contour, then a #4.