Same thing here with a 223.

Shots were erratic, beyond my erraticism. I was driving myself nuts figuring it was my load development, bad barrel and a few other possibilities. I pulled off the scope and the mounts were so loose they were wiggling to the touch. I tightened them up and used Locktite. Firm as can be. BUT, scope originally on the rifle possibly damaged by sitting in rings on very loose mounts. I swapped out scopes and was shooting slightly ragged holes at 100 yards. Anyone think it also could have messed up a SCOPE?