Quote Originally Posted by tcoz View Post
41.8, 42.1 and 42.4 are the three consecutive charges with the least vertical spread so I'm going to shoot a group of 20 with each charge. From that I'll use the charge with the best overall group.

I matched the ogive to base OAL in all of the test rounds to Hornady 168gr HPBT Match ammo which gave a 0.077" jump to the lands in my rifle. I'll work the final load down in 0.010" increments and see whether the groups tighten.

Unfortunately I only get to the range once every 2-3 weeks so this turns into a two month project.
I agree with your assessment, 42.1 looks to be in the middle of the group with least vertical dispersion. M12lrs was thinking the same thing, but since he was looking at it on a phone he probably could not tell your image is turned 90 degrees so what looks like horizontal dispersion was actually vertical. That is assuming your handwriting is not at 90 degrees. Took me a minute on a full screen to notice it. Let us know how it turns out.