I echo bp’s sentiments.

Additionally, I can shoot 5 round groups in the threes with my SPR at 200 all day long. The issue is not so much the quality of gun or shooter, but handloads.

For reference, at 600y with factory BH match I shoot about 10” groups. With my (Onyx/marks handload recipe) loads that shrinks to under 5”.

Try working up some handloads and you’ll see those shrink in half. Factory match ammo sucks for serious .223/5.56 precision work.