I quit shooting but only for a couple of hour or a dayor two, the I try again. Ask yourself, is it fatigue? If you find yourself getting more off-target after 30-40 shots your arm and shoulder are tired! Sometimes instead of shooting close I'll shoot farther. If I'm shooting at 20 and get the jitters, I'll go out to 30 or 40 and force myself to concentrate on a smaller target, the go back to 20, works for me!