Hey folks, got a bit of a head-scratcher with my trusty Smith & Wesson M&P 9mm pistol. When I let loose a rapid fire barrage, the darn slide sometimes just won't lock back after the last round. It's like playing a game of chance, no matter which mag I slap in. I've given it a good clean and lube, but it's still giving me the same runaround. Any of you fine folks dealt with this quirk before or got any bright ideas on what's causing this hiccup?