870 overhaul jams intermittently

[TonyBen]

I tested my 870 overhaul this weekend and was disappointed. Out of 50 rounds, the action froze up maybe 5 or 8 times after firing and I had to smack the butt of the rifle on the tabletop to get the action to cycle. At first, I thought it was the shell stuck in the chamber, but after I got home it was as if the action bar lock was not moving out of the way enough to allow the fore end to begin to move.

Imagine if you racked the action and it was fully closed but not fired. The you pull on the fore end without pressing the release lever. That's what the jam felt like. The action would not even begin to slide back to unlock the bolt.

Anyone ever seen this? Perhaps I need to polish the contact points or replace the fore end tube assembly? The only thing from this old Wingmaster that is original is the receiver, the fore-end tube and the trigger assembly (minus the flex-tab upgrade and carrier lift spring).

Tony.

[Synchronizor]

I would check out your action bar lock and hammer spring first. A bent lock or worn-out spring could cause exactly what you're describing. A rusty or dirty hammer plunger might be contributing as well. Unfortunately, getting to those parts requires the destructive removal of the hammer pin, and then you'll need a new pin and the proper staking tool to put it all back together. You've got some gunsmithing skills though, so that may not be too intimidating.

[The Rattler]

I experienced the same exact problem after refinishing the metal of my 1960 Wingmaster with Durablue. I took the refurbished gun to the Trap field, and just as you described, after 2 shots, I could not operate the action. Like you said, it was like trying to operate the pump action without either firing or pushing the release up that is located at the front left of the trigger guard. That continued to happen through about 1/3 to 1/2 of the firings of the first 15 shells. Then, it did not happen for the next 10 shells.

I read your post and Synchronizer’s reply and then discussed it with a friend who is most knowledgeable about guns. My friend suggested to refrain from lubing the rails and to operate the action a lot both with and without dummy rounds. This was to cause the parts to “wear” where the needed to do so to result in ordinary operation of the action. I did so without experiencing any repeated failures. I then oiled the railings and their respective “canals” in the receiver. So far, it appears to to be running smoothly.

[TonyBen]

So I figured out the problem. I was using Winchester target loads and apparently these loads are notorious for jamming even the most robust and reliable shotguns.

I took it out a while back and paid attention to how the jam was actually happening and it turns out the slide was releasing but the shell was stuck in the chamber. I had also polished all the slide release parts to make sure they were working properly.

I went out yesterday for some recoil therapy and tried Federal target, Remington nitro and Herters buckshot shotgun shells. All of them cycled without a hitch and I ran it hard. I ran about 60 rounds and my shoulder reminds me that I did it.

I've been trying to build my pump shotgun cycling instincts so I've been practicing cycling the action as fast as I can after lighting off a round. I got to the point that I can shoot three shells in a second.

I can only do this if there's two in the tube and one in the chamber. Any more in the tube and and the magazine spring (new factory Remington) can't keep up. I think I'll order a Wolff extra power magazine spring and see if that changes anything.

Again, I'm not doing this to show I'm a badass, I'm just doing it to develop pump cycling instincts/muscle memory. I'd like to be able to shoot and not even realize that I've pumped and chambered a new shell.

Thanks for the help guys!

Tony.