Shot a narrow OCW test at 513 yards today. Probably should have gone wider on the charge range. It appears there’s a super wide velocity flat spot between 74 and 75 grains. On the last outing there was a 23fps spread between 74 and 75 grains(only single shots at each charge), and today it was 3 fps. Charges were double weighed, so not sure what happened, but that seems too close a spread. ES in the individual charges sucked for two of the three, which probably played into the low ES across the range. Since this was the first go round loading the fired cases, I learned that my neck bushing isnt small enough. The Hornady brass necks have a tapered wall thickness, and my .335 bushing doesn’t size them down enough to for a mandrel or expander ball to uniformly establish the ID. So the base of the neck is sized and gets kissed by my mandrel, but the top of the neck was oversized. So the necks are essentially funnel shaped on the ID. Neck tension was all over during seating. I have another bushing inbound.
I loaded up 10 extra cases with br-2 and 215m primers(5 each).
Shot three of each at 777 yards. Ignore the group placement, as I adjusted to separate them. The second round of the BR2 load dropped low nearly to the 215m group.
BR-2 primer
215m primer
I took the remaining two rounds of each primer and shot them at 897 yards with the same sight setting. One of these rounds didn’t read on the labradar, but the ES of the remaining three was 3 FPS.
I loaded up 10 extra cases with br-2 and 215m primers(5 each).
Shot three of each at 777 yards. Ignore the group placement, as I adjusted to separate them. The second round of the BR2 load dropped low nearly to the 215m group.
BR-2 primer
215m primer
I took the remaining two rounds of each primer and shot them at 897 yards with the same sight setting. One of these rounds didn’t read on the labradar, but the ES of the remaining three was 3 FPS.