First, I didn't say it was the lube on the shell thing. Don't believe it is though I've seen something like that instructing 4-H trap with heavily used club guns.
I have seen various model pumps including 870's exhibit the symptoms the OP describes, gradually increasing difficulty opening the action after firing until the kid couldn't do it anymore and the coach had difficulty. If you consider the surface area of the hull being held in contact with a sticky chamber it doesn't take much. In all instances a THOROUGH cleaning of the chamber up to the spinning steel wool trick fixed it. Occasionally it was surface rust and a true polish fixed it. It's a place to start, quick and easy.
IMHO all new firearms should be field stripped and cleaned before use as a matter of course. You don't know what the manufacturer used as a preservative. It may not lubricate well, it may thicken in the cold, it may have oxidized sticky sitting on the dealer's shelf a long time. You just don't know.
(Yes, I'm having a particularly crabby day.)
You are making some good points. I know batue realizes that too. There are ways to make these express models really sing. I've done a few of them myself. Polishing the chamber and lengthening the forcing cone will get you a long way with how it operates. I also agree with battue, you won't have to do this with an older wingmaster, unless you are shooting trap competitively like I know he has. Like I said, mine is a '79 and it was built right from the factory. However, it's a sleeper because I made it that way
. You don't get in between 2 guys sporting Perazzi's in an Annie line and expect to win money, unless you have some tricks up your sleeve. Trust me on this one....
