Quote Originally Posted by gunnerblue View Post
Switching to the Lapua brass, with no other changes, led to a five-shot group of .265” measured center to center, 2739 FPS average, 17 FPS ES, 6.8 FPS SD. All rounds were loaded with a Redding full-length sizing die utilizing a 0.291” bushing and a Forster benchrest seating die.

It dawns on me that I need to shoot a ten-round group
I've had outstanding luck with the ADG brass in 300. We've shot several different boxes of ADG in 6.5 with the same pretty good groups you mentioned. I'd be surprised if the brass was hurting the effort.

I need to save some Hornady brass from a good shooting load to test out.

As far as 10 round groups.. although statistically superior; I find them impossible to shoot well all the way through. Even on the .223 bolt gun, I start introducing shooter error. And 300 WM with A-Tip would be way too expensive.