Here are a couple more good groups today. I was shooting it hot some, trying less case sizing, and shooting a different bullet, the 180gr SGK - which is the group that is low and left of the center aiming point. Rifle is working well - now to find a HUNTING bullet that it likes. It is absolutely in love with the 175SMK and doesn't care much what the powder charge is.
I find it very odd that sizing the case .002" less (slight bolt resistance) makes the group move left about 1MOA-can be seen in the vertically strung (my fault I bet) group at the bottom left. The group at the top of the top left triangle was rounds 15-20 without letting it cool - just shooting at a regular pace - some of that is probably eye fatigue from me too. The group that is centered above the bottom pair of triangles is made up of rounds 21-25 after some cooling, but not much. Shots 21-25 were aimed at the top point of the lowest right triangle and were sized. 002" less also.
The plate is the best group to date. 5 shots into .482 as best as I can measure. This was after letting the barrel completely cool and with .002" less sized cases. Aiming point was the end of the word "TARGET" on the shoot-n-see.
I find it very odd that sizing the case .002" less (slight bolt resistance) makes the group move left about 1MOA-can be seen in the vertically strung (my fault I bet) group at the bottom left. The group at the top of the top left triangle was rounds 15-20 without letting it cool - just shooting at a regular pace - some of that is probably eye fatigue from me too. The group that is centered above the bottom pair of triangles is made up of rounds 21-25 after some cooling, but not much. Shots 21-25 were aimed at the top point of the lowest right triangle and were sized. 002" less also.
The plate is the best group to date. 5 shots into .482 as best as I can measure. This was after letting the barrel completely cool and with .002" less sized cases. Aiming point was the end of the word "TARGET" on the shoot-n-see.
