^^^^^ This. IME regardless if the backer is intact and target is flat against it, by doing the above you can tell any yaw by how the actual bullet hole centers in the blackened outer ring. A clean backer just makes it a lot easier. Usually with custom BR bullets any yaw evident shows with-in the same group or target (if Score)........that is all record shots will appear similar provided one hit the same condition. Shoot the same load later or in different conditions and they usually show different- if not -you have a wide tune window and might just "shoot through" conditions.If you want to get a better look at the holes, turn the targets over, gently push the petals down and scotch tape them. They will look different when you turn the target back over. The group size will be easier to measure also.
Bret, thanks for the vote of confidence. At 600 yards I do a lot better than this point blank game.Clay I'm going with target backer.
I already know you can tune, and I know you know what you is doing.
So my conclusion is space/ gap between target and backer, and or previous holes in backer causing irrattic tears in target.
^^^^^^^^"Dusty is steering you right. A well-tuned rifle will make small holes with clean edges. When you see ragged edges and paper tears around a bullet hole, the gun needs work.
You can get tricked when the bullet holes start looking like a needle went through the paper because the gun is too hot and getting ready to throw a shot. It’s a fine line between the gun drilling and being too hot."
Bart