This week we had little kids visiting the house. As always, I rounded up the guns, emptied them, and put them under lock and key.

I keep a Remington 870 youth model 20 ga under the bed. It is stock except for a +3 mag tube extension.

When I went to empty it, to my horror, it would not release a shell from the tube to the receiver. I racked it 10 or more times before a shell finally exited the mag tube.

Clearly this would have sucked had I needed the weapon.

The weapon was pretty clean, though there was a bit of gunk on the mag follower.

I've always thought that the 870 was basically foolproof, but now I'm spooked.

Anybody have similar experiences and/or fixes?

Thanks in advance...

The culprit may be your magazine tube extension. Check to see that the mag tube extension fits flush with the original mag tube and does not leave a groove or gap between the two. A groove or gap between the mag tubes allows shell rims to be trapped there and held under spring tension, thereby causing feeding and unloading failures. This is standard inspection point for home defense or law enforcement shotguns.

Also vintage dependent, some in the late last century/early this century had actual dimples pressed into the mag tubes. Never heard or seen it first hand, but I'd imagine that the dimples when using an extension, could hang up shell, follower, or spring travel? I recall seeing a task specific tool for it (un-peening the dimples in the mag tube) Don't know if it applies to your situation, but might be worth a look?
Tell us what you find on it please!

The 870 is very much a case of NOT "rocket science".
The mechanism and system of operation is about as simple as you can get.

Basically, when you pull the pump handle back, the left action bar presses the left shell release outward, allowing a shell to be pushed into the receiver by the magazine spring.

When the pump handle is moved forward, the RIGHT action bar presses outward on the RIGHT shell release, allowing the next shell to move back in the magazine a fraction of an inch to the feed position.

When the 870 doesn't feed there's not much that can be wrong:
Check the magazine tube and extension for dirt/dried lube/rust/dents.

Check the magazine spring for proper tension/rust.

Check the shell themselves for pressure bulges.
When shells are left long-term in a shotgun magazine, especially in an extension, the shells may get compressed by the spring tension and develop bulges in the shell body between the shell head and the shot space.
If the shell is bulged it may fail to feed or chamber.

Check the left shell release for impacted grit and dirt behind the release between it and the receiver wall.
When the pump handle is pulled back, the action bar should press the shell release outward and a shell should be pushed into the receiver.
If it's dirty or rusty, it may stick.

Check the RIGHT shell release for dirt/rust, spring tension.
When the pump handle is moved forward, the RIGHT release should allow the next shell in the magazine to move back a fraction of an inch, then be caught by the LEFT shell release.

Check BOTH shell release to insure they are tightly staked in place. They should NOT be removed unless you have the special staking tool to re-rivet them in place.
A lose or un-staked shell release will cause failures to feed.

Thanks folks for the info.

This 870 has only 50 or so rounds through it. 40 or so of them after I added the mag extension.

I will check the shells for bulge/compression. I already cleaned the thing very very well.

I hope to gain more confidence in the thing. It has always functioned perfectly in the past...

One of the two shell stops has come loose and move toward the mag tube so that it will not move out of the way as it should to release the shell. They are staked (the flat indents) and the staking should match the staking on the reciever. If it doesn't, move the stop back into place and restake. They should not move front to back. Only the ends should move inners to outer.

quote:

Originally posted by flintsghost:
One of the two shell stops has come loose and move toward the mag tube so that it will not move out of the way as it should to release the shell. They are staked (the flat indents) and the staking should match the staking on the reciever. If it doesn't, move the stop back into place and restake. They should not move front to back. Only the ends should move inners to outer.

Do you happen to know where I could find a picture or two of the shell stops?

Thanks...

Al,
The only reason I mentioned those dimples in the mag tube on some is, the tubes follower on those guns literally, have notches ground into them 180 degrees apart to clear the indents. My thought was that with the extension in place, if those notches in the follower aren't in alignment with the dimples in the factory mag tube, feed failures could occur from the follower being unable to transition the mating of the extension to the tube itself.

No direct bearing, but my agency had some 870s. One began acting up a bit in a similar way, and as there was an authorized Remington repair station in town, I took it there. Spent about $50 of the taxpayers money and found that they hadn't really fixed it.

Bought a copy of Kuhnhausen's book on the 870 and diagnosed and fixed it myself. It stayed fixed, too.

BTW I am not a big fan of extensions anyway.

I would check for the dimples. I had the same issue in a 870 SP 12gauge purchased in 92.
In the end, I took a dremel and ground them down, then polished it. I haven't had any problems out of it since. I have shot about 300 rds out of it since. I keep telling myself, I will just replace the whole tube, but never get around to it.

How do like the youth 20gauge? I thinkng about getting one.