One of the things I do to test striker/firing pin function is to put an eraser tipped pencil in a vertical gun and pull the trigger to see what the pencil does. My 1911s shoot the pencil clear, similar with GLOCK, similar with XD, but my full size M&P40 - well - it just kinda shakes and goes upward less than half an inch from the breechface. The gun shoots great and I have robust primer strikes. Is this within the normal range of experience? Thanks.