I'm glad you got it sorted out....hope it's permanent eh. but yeah mine does this everytime. It's only with 3 1/2 inchers, all 2 3\4 and 3 inch cycle perfectly. I'm almost positive it's not a cleaning issue as I have taken it down many times and tried different approaches to oiling before re-assembly. Sometimes lightly oiled after using "crud cutter" on all internals and piston sleeve and then sometimes a little more oil than usual just to see. Same results either way. I make sure the mag tube is always cleaned and oiled inside to make sure theres nothing gummed up in there to slow down the shells travel from the mag. Cleaning gas ports and all the regular hiding spots lol. I wanna love this gun but right now it has me reachin for my old worn trusty 870. Maybe I was meant to be a pump man eh lol. Not sure what else to try,but thanks for listening and givin it a thought. Thanks again.