After running like a machine for thousands of rounds this Q5 SF has been giving me fits at the matches. Failure to go into battery, failure to extract & eject and now the slide won't lock back after the last round. I've pretty much fixed the failure to go into battery with changing OAL on the ammo and projectile shape. But after replacing the extractor and spring and trying 2 new mags, it went to crap on stage 4 today. It doesn't matter what ammo it runs or if I change out the Springco 14lbs recoil spring assembly for the stock one. New mags, old mags, every 2-3 mags full if fails to slide lock when empty. I almost threw it over the berm like a golfer with a crap putter today. I'm out of options and need some help.