Re: next 6mm varmint chambering?
Sheldon.... Never built one on a mod. 7, but I can not think of a reason why it would not work. Work in 700's, done that, work in AR-10's, done that. If it is a question of overall length, my reamer is set up to set a 95 Berger at 2.780", Sierra 107 at 2.790, and a 105 A-max at 2.775"
I like to blueprint the rails and radius and polish the feed ramp with most actions anyway. It really is not hard to make something work properly with a small amount of effort.