I use Lapua and Winchester brass and find it does make a difference on the top end of things, I'll get pressure signs 1 to 2 grains sooner in Lapua. 51 grains of IMR 4064 with 150 Interlocks is hard to beat. I run 52 in WW brass. Another load is WW brass, 165 NBT's with 56.3 grains R17. I get 2950 with in my Kimber Montana with 24inch barrel. I can swap in a 165 TGK same same. 57 grains of R17 with virgin Lapua brass and a 155 Scenar runs 3080 and tiny groups.

Last edited by spj; 01/01/24.