870 Broken or Short Stroking?

[45Fundi]

I have an amazing 1983 Rem 870 PM with a 20" bbl. Excellent condition and the most accurate slugger I have ever seen. Problem. When shooting it I often eject a hull clean, but it does not pickup the next shell and the next shell is firmly inside the magtube. It has the stock extra-heavy mag tube spring. 

 

So, is it possible to eject a hull clean and short stroke the gun? I don't think so... if anything I'd think the shell would at least leave the mag tube and jam up the gun, since the shell is left in the mag tube I'm thinking its a mechanical issue... experience or ideas with this?

[atomicferret]

Have you tried running dummy rounds through the gun?  What happens?

Have you tried holding in the action bar release and cycling through the magazine (without firing)?  what happens?  

Is it difficult to empty the magazine without cycling the gun?

Answers will help to diagnose the problem.

[kurtm]

Ahhhh, the good old 870 double pumper! Yes it is a mechanical issue NOT short stroking! Unfortunately, I forget the particulars of the fix, something with the side bars not being staked properly, fit of trigger housing? Get a pm over to Stealthyblaga, he was the one who wrote up the fix for this a while ago I believe. If I remember anything I will post it up.

[45Fundi]

Going to range now to do some tests... will post tonight.

[45Fundi]

according to the site, Stealthyblaga cannot receive messages :-(

[bishop414]

*Stealthyblagga

[45Fundi]

*Stealthyblagga cannot receive messages

[Matt in TN]

I had the same issue, and StealthyBlagga helped me fix it.  Photobucket killed the picture links, but the details are here:  http://forums.brianenos.com/topic/203384-help-me-troubleshoot-my-870/

 

I've fixed three 870's with this mod, and two of my friends have done it as well.  It works, and works great.  The mighty 870 rules Heavy Metal in the hills of Tennessee.

Edited October 11, 2017 by Matt in TN

[45Fundi]

I try and buy the most reliable and nothing exotic so I don't have these probs :-(

 

So, I suffered a leg injury and can't shoot and had 2 buddies with lots of downrange shottie experience shoot it and this time it was "hanging up" and leaving a shell on the carrier and the shell in the mag tube was held by the right shell stop only. I am now even more confused as when I shoot it fast the 2 or 3rd round in I get a click and I just have an empty chamber, but the hull cleared and threw normally. I guess I'll just sent it to Nighthawk and let them know whats up and see if they can make it run ($$$$) :-(

Edited October 19, 2017 by 45Fundi

[StealthyBlagga]

Sorry, I just saw this thread. I don't know why you can't send me a PM - I cleared out my inbox, so feel free to try again.

 

I have updated Matt's earlier thread to restore the photos of the action bar modification. However, before you send the gun to a gunsmith, I would suggest you replace the magazine spring with a brand new extra power spring - if the gun has run for many years without a problem, and is doing the same thing for multiple shooters, then a worn out mag spring is more likely. The factory spring is borderline anyway; I suggest you order a Wolff or Nordic spring and stuff it UNCUT into your gun (it will be a battle). If the problem goes away, you'll know that is the fix and you can start shortening the spring until you find the functional threshold. When you order the spring, order several so you can cut them to the optimal length and have spares on standby.

 

If the mag spring does not solve the issue, you should investigate the interaction between the action bar cam surfaces and the shell latches - if these parts show wear, replacing them may also help. Bearing in mind the age of this gun, wear in this area is not unexpected. Only after checking that everything is functioning as designed should you look at more drastic modification as described in Matt's thread.

Edited October 19, 2017 by StealthyBlagga