[USMC-Mustang]

I picked up a Remington 870 Express Magnum used (barely) the other day. The slide release is inoperative....meaning the slide (pump) will not lock in the forward position. Even tried it with a shell in the chamber and it'll still extract the shell without pushing the button. There is spring tension on the button, as should be, but it doesn't seem to be doing anything. Took it all apart and nothing is missing or out of place. Very strange. It would make it difficult to shoot with if the forward hand is pulling the shotgun snug to your shoulder and the slide keeps coming back. I thought I'd check here before I take it to a 'smith.

Any ideas?

Dave

[Jeff F]

If that 870 is not locking up like its supposed to, DO NOT SHOOT IT. You could be in for a world of hurt. I don't know what the problem could be but it sounds like something that needs to be addressed before attempting to shoot.

[dasanii19]

Sounds like somethings broke or someone didnt get put back together correctly.

[GigaBuist]

Yeah, I'd try field stripping it and putting it back together first.

And certainly don't try shooting it if it won't lock up!

[dasanii19]

Maybe thats why it was sold as "used" ?

[USMC-Mustang]

I have no intentions of shooting it as is. Someone can (and will) win the Darwin Award for such a thing. As per my original post, I stripped it down and put it back together properly (according to the manual).

Dasanii19, I didn't "purchase" it, I inherited it when a family friend recently passed. I hope you can understand why I want to fix it and keep it!

Now, has anyone seen this issue with an 870 before?

[chas08]

I experienced this a few years ago with a friend of mine who was building his own 870 for home defense. If the slide is not fitted properly it will prevent lockup. to test for this, unscrew the magazine cap slightly while trying to push the slide forwardand see if you can get it to lock. if it does then thats your problem. Take it to a smith and let him fit the slide. Just don't shoot it like that.

[Pete409]

For some reason, the Action Bar Lock is not engaging the action bar when the bolt is forward. The Action Bar Lock is that arm that sticks up and forward on the left side of the trigger assembly when the hammer is cocked. It's to the left side at the rear of the carrier. You have to remove the trigger assembly from the receiver to get a good look at this Action Bar Lock.

Perhaps this arm (Lock) is bent inward. Or perhaps the Action Bar Lock Spring is missing or broke. But, if there is resistance when you push up on the action release, then the spring is probably OK. Or, maybe the rear end of the Action Bar Lock is above the left connector instead of below it.

Or maybe the barrel is not fully inserted into the receiver, thereby not allowing the Locking Block inside the bolt to enter the locking notch milled into the barrel extension. Or maybe this locking notch in the barrel extension is full of crud or foreign particles of some kind and needs a good cleaning (although not likely according to your description).

It's just difficult for someone to accurately assess your gun's problem, but perhaps you can identify the problem yourself from these comments. Good luck. Let us know what you find.

[chas08]

Or... the spanner nut that holds the slide grip on has backed off and is contacting the barrel lug and not letting everything travel far enough.

[USMC-Mustang]

The barrel is all the way into the receiver. It also looks like the bolt is traveling all the way forward because the locking nut will engage (on the top) and I can see it on the top of the bolt.

I'll take the trigger assembly out today and give it a good look.

I greatly appreciate all the replies so far.

[chas08]

When you resolve the problem, please post the cause. It's got my curiosity in high gear:confused:

[Virginian]

I'm with Chas. Ran into this exact issue once when a buddy was fitting a synthetic stock. The magazine cap was stopping the forward motion of the slide just short of raising the locking lug all the way and locking because the forearm retainer was not seating all the way. Loosen the magazine cap and if that does it you need to either tighten the top ring retainer on the forend, or you may need to machine the forend a hair deeper.

[chas08]

Virginian, thats what had to be done to my buddies. A local smith removed a little more of the forend while we waited. It was a simple fix.