Got a Friend with a Moss 500E .410 pump shotgun Problem is not with a chambered round/shell, it won't feed a new one from the tube. Any round getting to the chamber will eject no problem. cycling the action will pick one up from tube maybe once in 10 cycles, to empty tube/ chamber, and only if gun is upsidedown(??). Before I break it down and clean it, anyone got any ideas what to look for? It does need cleaning but the action is free enough. I think a bit too much oil around reciever but at least not dry and rusty!! Thanks for any input.