i cant wait till monday to make a call to mossberg so i will ask if any know the answer. i have a model 500 that the fore arm ejects back on its own and spits out the shell every time i shoot. i have known 2 other people that have had similar problems with the 500 but never asked what the problem was. they just put them in the shop. is this a broken pin or slide or something? the gun worked great before so im hoping its something i could fix on my own thanks!

Sounds to me like the slide release is malfunctioning.I'm talking about the latch that you push to release the slide to eject shells without firing.It probably isn't locking up properly.What I would try first is oiling that piece sparingly.Work it several times and see if that frees it up.I would call Mossberg if you fix it or not. Since your friends had this same problem it must be a common failure and Mossberg needs to know.It could have a weak spring or something, I don't know. If Mossberg is any kind of a company they should repair it at N/C.It's probably something very minor and an easy fix.Good luck
Ruger Redhawk

in your post you say that everytime you shoot the slide goes back, and ejects a shell. if i'm reading it right it sounds like all is fine, i have several pumps, ithaca, remington, and mossbergs, they all work this way when you fire a round.

it throws the forearm back and ejects the shell almost like a autoloader. cant even hit paper with it half the time. i thought it was dangerous to continue using it so i will call mossberg on monday.

Once it's fired it should release so it can be pumped.But it shouldn't slide back by itself. Something just isn't right.I'm curious to hear what Mossberg has to say.
Ruger Redhawk

I've had the same thing happen with 500's with some "new" shooters. It appears that most of the "problem" is from not holding the shotgun too loosely on the pump.

Uncle Matt (in IL)

COULD be the gun, could be the way you're holding the forend! Quite a few people will PARTIALLY OPEN a slide action rifle or shotgun every ttime it recoils, a sort of reflex reaction!

i shot the gun from a rest, off hand and shooting sticks all with the same result. i have fired off many pump guns over the years and never had one open like this one. i guy i work with had a similar problem and cut up his hand because he held the gun in the area just behind the forearm. another guy i know had this happen while deer hunting. i think its gotta be a worn part or something.

I have this same gun and my pump does not come back after a shot. If your's does this something is not right. I would agree it's the slide release. It's mal-functioning. Let us know if this is a known problem.

I would shoot it off shooting sticks or something to hold the foreend up without my hand on the slide. If it still does this without your hand on the slide then I would say that the slide reaease is probably worn out on yours. My m500 has thousands of rounds through it and never done that.