precision

I've been playing around with different types of ammo for my DD MK12 SPR. I've run everything from 69gr FGMM, 77gr FGMM, 75gr Hornady Superformance Match .223, 75gr Hornady TAP, and CBC 77gr OTM. Oddly enough, the CBC 77gr OTM (clone of the Black Hills mk262 Mod 0 I believe) is the cheapest...