870 SM ISSUES

[WVU]

Purchased an 870SM (used) a while back. Been having issues with it not feeding/cycling shells. Ive stripped it down and messed and messed - just cant seem to remedy the problem....anyone else experienced this??

Any advice (and dont say buy a mossberg haha)....thanks guys


-WVU-

[bird]

Need more info to fully help you.  What shells are you having trouble with? 2 3/4", 3", 3 1/2" or all. Are you having trouble with ejecting a shell or with a shell exiting the magazine tube or feeding into the chamber?

[Deputy 14]

There are a few different things that it could be.  Like Cash said more specific information is needed.  Also like grizzly said it could be a mag spring issue.  Most of the time it is a problem with the shell carrier.  A quick way to tell is to put a shell in the mag tube and cycle the action (if you can).  While you cycle the gun hold it in front of you and watch the shell.  A lot of time the front of the shell will hit the top of the receiver in front of the chamber.  If it is hitting the top of the receiver clear the gun and close the action.  Lay something to pry against on the bottom of the gun between the mag tube and shell port.  Take a flat tip screwdriver and pry the shell carrier upward and try to cycle the action again with a shell while you watch it and see if the front of the shell is still hitting the top of the receiver, then repeat if necessary.  Don't try to tear it off but you can use more pressure  than you think when you pry up on the shell carrier.  Like I said I don't know if this is the problem your having but its the most obvious one that I can think of  Hope this helps.
Also anyone else that reads this happens on almost every 870 I have ever worked on. If you take the time to do this it will make your gun cycle much easier and not beat up the crimp on your shells when loading/unloading several times.

[ccleroy]

Sure you're not short shucking?

[FullChoke]

I had problems with the ejection of shells from my new 870 last year and found a solution that cleared it up. Since you did not specify the exact nature of the trouble, this may or may not be helpful. Check it out.

http://oldgobbler.com/Forum/index.php/topic,8742.msg102298.html#msg102298

Good Luck.

FullChoke

[WVU]

Need more info to fully help you.  What shells are you having trouble with? 2 3/4", 3", 3 1/2" or all. Are you having trouble with ejecting a shell or with a shell exiting the magazine tube or feeding into the chamber?

All shells.

Exiting magazine tube and feeding into action. If action is open and a shell dropped in - its will slide shut with no issues. Just cant get it to feed from magazine tube up into action when pump is slide back (cycled). Shell stays in the tube.

[Kylongspur88]

Mine has done that a few times. Almost like it got snagged on something and just didn't feed the shell. Only with 3.5s. Idk. It has only done it a few times and never in the field hunting. When it get some time I'll take it apart and try to figure it out.

[WVU]

Thanks Gents!

[mossyoakpro]

Is there a good schematic drawing somewhere on totally taking the 870 apart like was stated here?  I have a few and I have never had them apart like that....I may get the same problem one day.

Thanks!

[West Augusta]

Mine does this also.  I have stripped and cleaned it, stretched the spring and it still hangs in the magazine occasionally.
I plan on stripping it again now that the season is over.  I thought that it may be some residual cosmolene in the workings so I sprayed it with WD-40 which helped for a while.

[bird]

Mine does this also.  I have stripped and cleaned it, stretched the spring and it still hangs in the magazine occasionally.
I plan on stripping it again now that the season is over.  I thought that it may be some residual cosmolene in the workings so I sprayed it with WD-40 which helped for a while.

Mine will do this with the last 3 1/2" shell in the mag tube.  I decided to replace the spring and follower with new from S&J Hardware spring & follower kit made more robust than the factory.

[mossyoakpro]

Thanks for the info....Now I know what I will be doing on saturday 

[mossyoakpro]

I just took mine apart sitting in my office....I should have been doing this years ago.  I can really clean them up now!!

Thanks again!!!

[troutfisher13111]

I have an 870sm with similar issues, this has been an informative thread.

[allaboutshooting]

It's also a good idea to invest in a good magazine tube brush. With a little bit of Hoppe's #9 or your favorite solvent and a good magazine tube brush, you can easily scrub all the gunk and rust out of the magazine of your gun. It's hard to imagine how much "stuff" can accumulate in there.

Just like the bore of your gun, the magazine gets very dirty. I've had folks send me pictures of the nasty black gunk they've removed from their magazines, just like from their bores.

While you're doing that, it's a good idea to take a look at your spring. They can rust and if a gun is left loaded, the tension can be reduced over time.

Thanks,
Clark