Here's a few updates:
Pushed up to 45.2 H4831sc. No pressure signs but SD went to shit over 45.0. If I were to use this powder, I would run 44.9 which yields me 3040fps. Lapua brass, 26" barrel, 8 twist.
Yesterday I tried H4350, only 3 shots per load.
40.4: 2970 SD:2
40.6: 2970 SD:3
40.8: 3000 SD:5
41.0: 3022 SD:2
41.2: 3030 SD:3
Accuracy was spectacular on several, but they were only 3 shot groups. I think I have a node at 2970 and another at 3020. I'm thinking of pushing up to 41.8 grains next trip to see if I can find another node.
ETA: Lapua brass has significantly less case capacity than Hornady and I would not recommend basing loads off Hornady brass load data.
I friend was shoot his the same day. Also Lapua brass 1-7 criterion barrel. 0 round count before today (mine was at 40). I think his barrel is chambered for factory ammo and probably has a longer threat. His loads were about 80 fps slower than mine. Not sure if due to throat, twist, or break in. Probably combination of factors.