Any chance the front action screw or scope mount screw is hitting the bolt head? Color it with a sharpie. Hate to sound like BS, but you gotta nip mechanicals because the best ammo is schit otherwise. I went through the ringer with my 6x45. Using the same load all the way through the process and it went from 1" 2 in one out crap to nice 1/2" groups.
