I have several 870s all wingmasters I guess.but have seen and been around a slew of the express's.have never seen are heard of the problem described by cobra.EXCEPT when bad ammo was used.living in a very humid area the old paper shells would swell.even the brass base.and that would make extraction hard.he-- it even made loading them in the chamber hard.but cheap as we were we'd git er dun, one at a time..I think the 870 is one of the most reliable pump shotguns made.most would not beleive the torture that I have put two of them through hunting in the jungles of central america both wingmasters in three inch mag.one was a loaner for the natvives if they did not have one to hunt with.whewooh,they took care of it like a redheaded stepchild.they always functioned.leaves,twigs and what ever in the way of the slide bars and bolt,would just get sheared are crushed and the guns would fire.Then you could blow dead deer on your cow horn..great shotguns.heck, you could even blow dead deer out of the barrel and action of the 870s and be heard all over the jungle.