J E,
No specific details that I think will help . . . for what it's worth . . . as I'm a bit outside the box from time to time.
Shooting a 338 RUM Rem 700 Sporter, braked.
Been through all kinds of bullets. Liked 262 Wildcats best. Not a great bc. Ran out....
Went to 300 SMKs. shot lights out. Very impressive. MV = 2735.
Got some Berger Gen I. Shot even better again @ 2735.
Figure Gen IIs will do likewise.
The interesting thing was that the load I ended up settling on is a case full of 50 BMG and the Berger jammed way hard into the rifling.