Rem 870 clone - sticky slide

[Tokarev]

I have a chinese clone of rem 870 which works fine with its own bbl, but with Remington bbl installed slide becomes sticky every about 3d shot fired. Opening the slide is sometimes possible by jerking, and sometimes by pulling hard. In other words it's a lottery and a royal PITA because I use Remington bbl for clays. Coincidentally, Rem bbl fits the receiver better and there is virtually no play in any direction. The chinese bbls play a lot - can be twisted and tilted quite a bit.
Looking at the 870 bolt and bbl I just can't figure what can cause stickiness, as pulling back on a slide applies lots of pressure on the lug to pull it out of the notch in the bbl. Am I missing anything?

[AggieEE]

Afternoon Tokarev, I think what you are seeing is the difference between metric manufacturing and inch. Think of the metric and inch pattern FAL. Not to mention the great quality control from the Chinese. Try cleaning everything off dry. Then take a Markalot and blacken everything that fits together. The locking lug on the barrell extension, outside of the barrell, etc. Put it back together and cycle it through several sticking cycles. Take it back apart and see what is rubbing. Don't forget to check the action arms from the fore end also. If you don't find anything take some pictures maybe somebody with more experance than I can see something off. Good Luck.
AggieEE

[cajun shooter]

I would check the slide action bars and inside the receiver where the bolt passes over the piece on the left which is called the barrel extension. Also look at the fit for the extractor in that same piece. Look for any shiney spots on all moving parts. Take your time and do it slow. You might get lucky and make it work. The Chinese way of making firearms is not even close to the old 870's which I still shoot. The Ithaca 37 and Remington 870 are the best pumps ever made.

[10 ga]

Cajun!
Winchester Model 12!
Set the standard and still runs in front of the pack. You just can't buy a new one. 10

[starnbar]

This may work for you or maybe not if you have a friend see if they will let you borrow the 870 bolt out of thier shotgun.

[Tokarev]

Starnbar:
The bolts are incompatible, because this one is a box magazine fed and the bolt has a provision to feed a round forward from the box mag.

I've already narrowed down the issue to a rocking lug before posting the question. When I pull the slide, the tab on the sliding plate at the bottom of the bolt is supposed to push the rear of the rocker and disengage the lug on top of the rocker from the bbl extension. And that's what is not happening. The slide moves back by about 1/8-1/4" - just enough for the bottom plate to start pushing the lug, and gets stuck.

To me that sounds like there should be something in the contact area of the lug and the notch on the bbl extension, but I can't see any burrs etc. and both working and not working bbls look exactly the same in that area.

[Thin Man]

If the only part you have exchanged in your original shotgun is the barrel (original to Remington), I would suspect looking at the clearances between the action tube and forend against the Remington barrel. This can be caused either by the Rem. barrel being slightly wider than the original in some area(s), or that the forend has shifted (rotated?) during the installation (or as original position). Apply layout fluid (Dykem) or a bright color felt tip marker to the bottom and sides of the replacement barrel, reinstall the barrel and cycle the action several times. Remove the barrel and inspect for signs of friction. If a permanent correction is required to either the barrel or slide components, conventional procedure is to make these adjustments to the least expensive part that will correct the problem (so that if replacement of that part is later required, less expense). This is an easy decision if parts are available for your shotgun. If they are not, corrections might be directed at the barrel (not cheap, but easier to replace). Good luck.

Thin Man

[mckutzy]

This sounds like a similar topic on a major Canadian gun forum that I was just looking at, with one of these same Dominion arms Grizzly Mag fed shotguns. There is some differences with these guns, and not 100% compatible with Remington parts, some need fitting but for the most part just use the oem parts from the gun.

OP- Does this problem occur with the gun unloaded or when loaded and shooting? what kind of ammo are u shooting?
Cheap bulk packs with steel base shells like that are sold at wallmart are prone to sticking in chambers due to steel base expanding differently than brass.

[Daniel Boone]

The solution is to get rid of the cheap Chinese gun and buy a real Remington.
There is no benefit to buying second best.
A cheap 870 can be had used for as little as $200 if you are in the right place at the right time and don't mind shooting a Express model.

Would be like the old Hee Haw joke - the guy says doc it hurts when I do this and the doctor says - well then stop doing it!

[Tokarev]

> The solution is to get rid of the cheap Chinese gun and buy a real Remington.
Remmy does not make box mag fed gun yet.

[Tokarev]

The assessment that it was related to the locking lug was incorrect.


I would check the slide action bars and inside the receiver where the bolt passes over the piece on the left which is called the barrel extension.

You were right, this was receiver issue. Some guides inside the receiver had burrs on them, after filing the burrs the action seems to be working fine, need more testing to confirm that 100%.

The burrs were not there when the gun was new, it seems that receiver steel is just too soft.
I am still puzzled how come this only occurs with Remmy bbl though, as bolt is completely disengaged and is guided thru the receiver when lockup occurs.

[nanuk]

Sometimes the soft metal can cause an issue until it has worn enough to not burr.

any thoughts on using a moly grease on the burring area?

[Tokarev]

If I've only known the burring area!
I am still struggling with the action. Last time we took it to trap range it looked almost like the problem was solved by polishing the slides and their guides, but after a box it stuck again.

[Tokarev]

Problem solved!

Root cause was overly tight chamber of the Remington barrel: 0.795".
The barrels made in China that came with a gun, and the Mossberg rifled barrel have 0.811" chambers.
Once I rimmed and polished the chamber to 0.811", sticky slide problem no longer existed.

It was a very confusing issue to deal with until I started measuring chambers for an unrelated project. It just did not occur to me that a barrel, made by Remington, can be a root cause of the problem.

[tomme boy]

Remington 870 Express barrels are garbage. It seems that most do this. I will not buy anything made by them anymore. It seems every year they make their stuff cheaper and cheaper. I tried to buy a 308 win in the 700 line a couple of years ago and I looked at 5 differant ones. ALL had the chamber bored offcenter.