Here's an update: fired two seperate groups of 3 shots each + 1 cold bore shot. 1.8 mph average breeze, 31.6 degrees F, @ 100 yds. Cartridges were loaded with Varget, with a COL of 2.805" for a .030 jump to the lands.
First group averaged 2841 fps with 31 grs. @ 1.944" 3-shot group. 133 fps extreme spread.
Second group averaged 2984 fps with 32 grs. @ 3.187" 3-shot group. 58.87 fps extreme spread.
The 69 gr. Nosler CCs did not stabilize at all, they keyholed horribly :( with tears at .162" over bullet diameter. I was debating whether or not to use them for varmints 'cause they probably would cut them in half lol ;).
Back to the drawing board for a lighter bullet, the throat is extremely long though, probably eroded. So my jump to the lands is gonna have to be a lot longer.