Had that happen awhile ago with my 460 magnum. Was a few inches off at 50 yards when I hadn’t shot the gun in several months. Tried shooting it one handed and all of a sudden I was hitting fine. Too hard of a grip with my support hand combined with anticipation of recoil really threw me off for 40 rounds. I think I was squeezing my hand along with the trigger in anticipation of the bang. Or kaboom really. Relaxed a bit on the next range trip and it got better.