Went out early this morning with a friend to really nail down a good long range load with the least vertical dispersion. I had shot the 41.8 grain H-4350 load with the 139 grain Scenar at 600 and was pretty happy, but wanted to see how it performed at 1000.
I charged 100 cases from 41.7 to 43.5 grains, 10 of each in .2 grain increments. No bullets were seated until ready to shoot at the range. I always take my press and do it this way.
Here's how it went. My buddy is in the pits with a radio. I seat 2 bullets in two cases at the starting charge and shoot them. If they group with no vertical, I seat 3 more and shoot them for results. If the first two have a bunch of vertical, I skip that load and move on. This is great because you don't end up having to pull bullets and dump powder back at home. I only shot 26 rounds to achieve a good load with the least vertical dispersion...
Four to the right of my hand and one above and left. About 4 inches of vertical. Nice group too. Shot in 8-10 mph crosswind from 3:00
42.5 grains H-4350
139 grain Lapua Scenar
Federal 210M primer
.015" off of the lands; 2.830" COAL
Velocity will be determined later.