870 Double Feed

[marklbucla]

I took out the 870 stable today to try and diagnose/clear up the issues with the ejection as mentioned on this thread: http://www.thehighroad.org/showthread.php?t=403099

In exchanging various parts, I've found that an old Wingmaster forend tube will produce double feeds, while a C&R Wingmaster Tube and a new Express tube did not. The double feed looked sorta like a double feed in a pistol- one shell on top of the other sitting on the carrier.

It happened with three different bolt groups, but I only tried one old style slide assembly (or bolt carrier, whatever that little plate thing is called). I ran out of ammo by the time I noticed this, so I didn't try the whole group in any other guns.

The offending forend tube did make the action feel extremely smooth. Any ideas as to what causes this phenomena?

 

[PA4476]

The rods on the pump tube control when the shells in the mag are released. Each side of it works the shell catches inside the receiver.

It's possible you have some issue with the shell catches.

I have a 58 Remington, exact same operating system as far as the two flat rods and shell catches. Mine would put one on the carrier and then dump the next one out the bottom of the gun. It was the left hand shell catch on mine, it had gotten bent by a former owner.

 

[marklbucla]

Could the width of the rods be the issue at all? I noticed that some have to be bent inwards, while others need to be bent outwards.

 

[Fred Fuller]

I'd guess it's worn or damaged action bars, which engage the shell stops in sequence to release rounds from the magazine. Could be a cumulative size issue between the action bars and the shell stops in that particular gun, it's hard to say. All it takes is a few thousandths of an inch on both parts.

Since you seem to have narrowed it to one action bar assembly, just replace that one. Spares show up on eBay, Gunbroker etc from time to time.

hth,

lpl

 

[Virginian]

So, I take it you still have not solved your original extraction/ejection issue?

 

[marklbucla]

If I use known good bolt assemblies, it works fine. I've got it narrowed down to that. I haven't tested the opposite though: using the bad bolt assembly in a known good gun.

 

[marklbucla]

Lee,

Just to be clear, it would only be the forend tube that should be discarded, not the slide assembly (or bolt carrier, whatever that little plate thing is called that the bolt sits on)?

Thanks!

 

[Fred Fuller]

it would only be the forend tube that should be discarded, not the slide assembly (or bolt carrier, whatever that little plate thing is called that the bolt sits on)?

If swapping out the fore-end tube/action bars solves the problem, I'd say yes- tag the one that causes problems and bury it in the parts bin for a rainy day.

Hope you get it resolved,

lpl

 

[marklbucla]

Follow Up:

I took out the stable again today since Remington sent me a new extractor group. It turns out that the particular forend in question gave me the best performance in ejection this time around, without any double feeds.

 

[Virginian]

Please look at the parts diagram and tell me what an extractor group is? Seriously, you lost me. The only extractor I know of is the hooked piece that goes on the bolt.

 

[marklbucla]

The extractor, extractor spring, and the extractor plunger.