I have a 870 12 gauge wingmaster that is probably at least as 40 years old if not more. I inherited it from my grandfather who never used it. I use it for Dove hunting and keep it clean. Last outing things got really going and my barrel was getting hot. I was having constant shell ejecting problems. I've heard everything from built up plastic,cheap shells to the need to polish the chamber. Any ideas out there?

Could be anyone of the ones you mentioned

What shells were you shooting?

I had a mixture, Rio's,Winchesters,Federal. Day before the gun was not acting like this with the same shells.

Look for any defects or debris/build up in the chamber. Likely the culprit. Wouldn't hurt to give it a little polishing.

I was hunting in a field opening morning a nice young man had the same problem, he was shooting Estate shells. I got the stuck case out of the chamber and coated it with Rem Oil. The extractor looked and acted fine, he put it back together. it worked for a while then started sticking again. It too was an 870 magnum.

Poor guy, dropped his magazine cap, searched and found it, the realized his plug shot out too, last time I saw him , he was working on a stick to use.

so to answer your question "all the above" or take it to a gunsmith

The only low brass ammo that will work in my 870 is AA Win, any other hangs up. Works fine with high brass and Mag ammo.

My 870 Wingmaster will pretty well eat anything with no issues.

never had probs with the 870 with any type of shells

I had the same problem(s).

Polishing the chamber and keeping it properly lubed would pretty much eliminate plastic build up and sticking shells.

When I was shooting a lot of skeet, I'd usually have to go hit it again in 3 or 4 months.

I put steel wool on a dowel & used some liquid chrome polish (what was handy).
Lapping Compound or anything similar would work fine.

Thanks for this. Went out after another really thorough cleaning and she performed much better only a couple times on the Rio shells. I probably should just put this gun up for safe keeping since it belonged to my grandfather, but I like shooting her!

No sence in putting it up, a wingmaster of that age is probably better built than anything big green puts out today. That being said, it's a mechanical tool that needs a little maintenance. Pull the barrel and clean the bore really good. Then take a brass brush (12 gauge if its a 12, 20 if its a 20 ext) put it on a short pistol rod and chuck the other end in a drill. Coat the brush with flitz or something similar. Then polish out the chamber well. After that clean it all put really good, gun scrubber and clean cotton swabs. You want a clean dry chamber and bore. While the barrel is off clean out the extractor really well, tooth picks and q tips. If your familiar with everything pull the trigger assembly and clean it all good. Put it all back together and rock on. If your not comfy doing all that and your in far north east tx bring it to me and ill do it, or help you do it. Im stuck at the house and bored for a while. Im north east of Bonham and recovering from spinal fusion surgery.

I catch myself not fully pumping my old 870 while trying to hurry up for a follow up shot from time to time. Mine is about 50 yrs old I believe and was my grandfathers. Not saying yours doesn't have a problem but just make sure you are working the pump action fully and not short stroking it. With that said mine is prob a little dirty and would prob work smoother if I gave it a good cleaning.

Thanks trigger time and SapperTitan. I may have been short stroking it between shells in a hurry. Either way I cleaned her well. I'd like to tackle the trigger assembly but not sure about that.

Plastic shells sweat and the chamber is hardley ever cleaned properly! I inspect mine ever year. Shooting in winter it is easier for the sweat action to occur. Take apart and lite steel wool or brass brush and buff them out then thin coat of Remoil or your prefered oil.

Jeez guys.. No one thinks a 40 year old gun has a weak extractor spring?

Not likely, I have never seen one go bad.

Doesn't short stroking cause the next shell in the magazine to try and load before the fired shell is fully ejected?

Maybe I'm missing something here but my experience is that short stroking is different than a shell that was stuck in the chamber in the first place due to any of the previously posted possibilities. My number 1 encountered cause of stuck shells was cheap walmart shells. Dirty chamber was #2 and rough chamber that needed polishing was #3 cause.

I think you can still short stroke and cause a jam up even with a pristine clean polished chamber and perfectly functioning extractor.

The ones that were truly stuck in the chamber (rather than a short stroke jam-up) required a cleaning rod through the barrel or dropping something with some weight to it down the barrel and using inertia to bang it loose.

Whatever the case, I hope you get it sorted out. It's a frustrating thing to happen when the birds are flying fast and furious!!