So I recently finished building my 300 WinMag. It is Defiance Action, Manners stock, 28” Proof CF 1:9 twist barrel. I set out to do a load developement with 215 Bergers and found myself confused.
Load = Hornady Brass, 215M primers, CBTO 2.95 .010 off the lands. It has custom throat.
I started...