Consistent first-round double-feeds with 870

[Shmackey]

My new-to-me but well-used 870 Wingmaster is acting funny.

I load four snap-caps, making sure to insert each one fully. Then when I pull the forearm back to chamber a round, two snap caps come out. (The first one comes out all the way, and the second one follows it, sticking out as far as it can in a straight line with the first.) This causes a really nice jam; once I clear the jam, though, so that the first round is out and the second is sitting on the carrier, waiting to be chambered, I can cycle through all the rounds with no problem. It only double-feeds on the first cycle, and it does it every time.

Whatcha think? Thanks.

 

[SDC]

Does it happen if you only load 3 in the tube? I can't think of a reason why the shell stops should act any differently between the 1st and 4th rounds, so maybe it's the strength of the magazine spring; when it's fully loaded, there may be more force pressing the shells against the stops so it may be more prone to "skip". If that's the case, you may need to get your shell-stops replaced.

 

[mnrivrat]

Specifically the left hand shell stop which is likely worn to a point to give the trouble you discribe. SDS had it right when indicating the reason for only the first rounds out of the mag tube causing the problem. The additional push from a fully loaded magazine coupled with a worn shell stop is the most likely cause of the problem. Try a good cleaning first in case some debris has lodged behind the stop and then go from there.

 

[kudu]

Snap caps may not have the exact rim dimenson necessary to keep it from popping past under spring pressure. The real test is to see if live shells work, in a safe area please. The only thing snap caps are designed to do is for absorbing fireing pin hits, not for cycleing through the gun.

 

[Dave McCracken]

Like Kudu said, test with live rounds in a safe area. The red and clear plastic SCs do not cycle well.

 

[C.R.Sam]

And if function is similar with real rounds....

Heed advice of mnrivrat above.

Sam

 

[mnrivrat]

While both Kudu & Dave bring up a good point , remember that even if the double feed is not present when checked with live rounds you will have variation in the head size of live rounds also. (particulairly between different companies) If only the first couple snap caps give a problem and the rest cycle through just fine it tells you that there is a functional difference in the stability of the shell stop under different load pressure . For the price of a shell stop it realy pays imho to replace it or adjust it, rather than have a potential hit or miss feed problem.

 

[Shmackey]

Great advice. Anyone know off the top of their head what the parts numbers are for the shell stops, follower, and such? Maybe it's time to go to Brownell's...

I'm not a genius with shotgun innards but I think I could figure it out. Am I right in assuming that the safety does not block the firing pin?

Thanks.

 

[mnrivrat]

You are correct - the safety does not block the firing pin.
LH - Shell Latch : Rem Mfg# 102310
RH - Shell Latch : Rem Mfg# 102315
Shell Carrier Assy : Rem Mfg# 101185 (should have nothing to do with the feed problem)
Forend Tube Assy : Rem Mfg# 102320 ( this is the tube and action bars - the wear would have to be very significant before this part would give you a problem, but it is the part that has the mating surface for activating the shell latch)

I'm thinking the only part/s that you should have to be concerned about would be the Shell Latch/stops . If you observe the shell latches you will be able to determine how they operate in and out during the action cycle to determine the shell feed from the tube. This will allow you to determine which is giving you the trouble depending on when they are activated. They cost under $15 ea.
On a side note however they are staked in place and require re-staking when changed. They make a special tool to do this with so you may want to consider having it done . You can re-stake without the tool - it is a bit more difficult to do a good job however.

 

[dfariswheel]

Be advised that's there's more to changing Remington shell stops than just pulling the old ones out and sticking new ones in.

The stops are staked in place, and a special staking tool is required to re-stake the new stops.
Replacing the stops isn't a major job, but you MUST have the right staking tool.

I'd recommend cleaning out the receiver throughly and re-lubing to see if the problem is just grit and gunk, then shooting it with live ammo, before undertaking a release replacement.

Brownell's numbers for shell stops are:
Left hand--767-102-310
Right hand--767-102-315
Follower--767-928-030

The safety blocks the trigger, not the firing pin.

 

[wintermute76]

I had that problem once, it was good and dirty after a weekend of shooting clays and probably a bit of cosmoline behind them as it was brand new (didn't think of cleaning behind them) . Pulled it apart and cleaned it, been good ever since.