870 sticking randomly

[wats6831]

I cannot figure out what's causing it.

It has been cleaned and lubricated, including the trigger group.

I have updated the dog follower spring and hammer spring.

I just ran about 80-100 rounds through this without this problem.

Then now for some reason, about every 3rd round the action sticks shut, but NOT if I pull the trigger and pump.

It only sticks if I use the slide release to cycle the rounds.

It doesn't stick every time, it's random but repeatable.

I've had it apart more than once and I cannot find anything wrong.

I'm just stumped.

The video is using real weight dummy loads, but it does the same thing with Hornady Critical Defense and a few others.

Again firing live and pumping it this doesn't happen. Only when cycling the round with the slide release.

 

[jmr40]

A few years ago they had a batch get out the door with rough chambers. I had one that did that occasionally. I contacted Remington and they referred me to a service center close by. I made an appointment, they polished the chamber and the problem went away.

I've since found that it is a fairly easy DIY repair. A wire brush made for a 12 ga attached to a drill can be inserted into the chamber to clean and polish the chamber.

Your problem may be something else, but a thorough chamber cleaning won't hurt anything and may help.

 

[243winxb]

Locking bolt # 37 ? Stickkng? https://www.gunpartscorp.com/gun-manufacturer/remington/shotguns-rem/870/parts-list-rem-870

If using dummy shells, or reloads, from fired hull, the metal has expanded & needs sizing.

 

[JCooperfan1911]

Some judicious use of a bronze bore brush chucked into your hand drill will cure that right up.

 

[Blue Brick]

I cannot figure out what's causing it.

It has been cleaned and lubricated, including the trigger group.

I have updated the dog follower spring and hammer spring.

I just ran about 80-100 rounds through this without this problem.

Then now for some reason, about every 3rd round the action sticks shut, but NOT if I pull the trigger and pump.

It only sticks if I use the slide release to cycle the rounds.

It doesn't stick every time, it's random but repeatable.

I've had it apart more than once and I cannot find anything wrong.

I'm just stumped.

The video is using real weight dummy loads, but it does the same thing with Hornady Critical Defense and a few others.

Again firing live and pumping it this doesn't happen. Only when cycling the round with the slide release.

Emptying a shotgun by cycling the action is a no no. Turn it over and release them from the magazine.

 

[Virginian]

Jeez; it only sticks using the bolt release. This isn't shells sticking in the chamber. Your bolt release is likely bent.