USMC clone range testing: It's all about the node

Spent a wonderful but BRUTAL day at the range with my USMC clone (924K w/ CMP stock, Criterion barrel, Hi Lux Unertl) trying to work up some loads. I say brutal because I put 100rds through it in a Tshirt. Pretty sure my shoulder should be amputated. Anyway, the more time I've spent with the 1903 (and it's replacement), I've come to notice that the closer you come to military specification loading, you usually find an accuracy node. I was ladder testing some 155 Amax with IMR 4895 and got the following group at 2745fps.

Couldn't get the 175s to group as well, but the best group was right around 2726fps with IMR 4350.