I use 27gn Varget or ADI 2208 behind a 55Vmax, compressed load which is a pain. Very accurate.
20 inch 1-8 twist AR variant, Rock River Arms. Haven't tried that particular combination yet in my others which are all 1-7
I should say too, its a safe load in my gun but I don't reload cases multiple times, I use once fired cases in my reloads, shoot em and leave em.
Bookmarks