Strange 870 feed issue, need advice.

colostomyclown · August 20, 2011, 10:24 PM

Took my 1981 870 Police Wingmaster out this week twice and have put about 225 shells through it, all low base federal target loads. The gun seems to be in great shape, although it's having a strange feed issue. My technique I feel is sound, I rack hard and clear to the back and forward, no shortstroking...what happens is a shell will fire and eject fine. When the next shell drops onto the lifter, its almost as if either the bolt or the lifter are making the shell bang into the bottom of the barrel itself rather than going straight into the chamber. It's easily cleared, I rack backward after it hangs up and forward again and it will fire.

Any idea whats going on here? Shells stops, extractor, ejector seem just fine.
Basically picture the shell feeding in to the chamber low and impacting rather than going directly into the chamber like normal..have never had this issue before on any of my scatterguns. Usually its double feeds cause of bent shell stops or bad extraction or shortstroke...

Ridge_Runner_5 · August 20, 2011, 10:40 PM

Might want to check the end of your mag tube for debris or rough spots. Lightly oil the inside of the tube near the receiver.

Lee Lapin · August 21, 2011, 02:02 PM

Carrier dog spring and/or plunger might be sticky - see Part #6 at http://www.urban-armory.com/diagrams/rem870.htm . Pull your trigger plate assembly and give the carrier dog spring and plunger a drop of lube and see if that helps...

lpl

colostomyclown · August 21, 2011, 03:36 PM

Lee,

since I'm converting to Flextab capability and swapping these parts out I'll probably just replace the spring at the same time. Based on the issue and what youve said, really this seems like the only possible variable. If that springs bad or gunked up the carrier will be pretty lifeless. It's a 30 year old gun and has probably never been swapped out and I'm inclined to believe it was bad because it was spotless and well oiled when the issue was occurring.

Strangely, the gun started off functioning perfectly and worked its way into acting like this. Maybe the spring went bad right then and there..

Lee Lapin · August 21, 2011, 03:59 PM

It could happen, I suppose. On modern 870Ps the carrier dog spring is heavier than on standard 870s, I don't know when they started using the heavier spring though.

Hope that fixes it for you,

lpl

colostomyclown · August 21, 2011, 04:29 PM

Thanks!

A little disclaimer for everyone reading the thread - this is a 30 year old gun. The issue's probably a minor one. Once it's fixed, I'd bet my life on this gun many times over. The all steel construction of the older 870s and 870ps are really a thing of beauty. This gun is smoother than polished glass, it really is a joy to shoot and handle.

chack · August 21, 2011, 04:35 PM

I wonder if the magazine spring in it is a standard length spring instead of one for an extended mag.

bamaranger · August 23, 2011, 10:41 PM

We had several "870 Magnum"'s in the 15-20 yr old range (not Police models) as duty shotguns that exhibited the same failure, the new shell striking the lower lip of the chamber. Clean and lubed did not really help.

Carrier dog spring HD did the trick.

August 20, 2011, 10:24 PM	#1
colostomyclown Senior Member Join Date: February 22, 2009 Posts: 613	Strange 870 feed issue, need advice. Took my 1981 870 Police Wingmaster out this week twice and have put about 225 shells through it, all low base federal target loads. The gun seems to be in great shape, although it's having a strange feed issue. My technique I feel is sound, I rack hard and clear to the back and forward, no shortstroking...what happens is a shell will fire and eject fine. When the next shell drops onto the lifter, its almost as if either the bolt or the lifter are making the shell bang into the bottom of the barrel itself rather than going straight into the chamber. It's easily cleared, I rack backward after it hangs up and forward again and it will fire. Any idea whats going on here? Shells stops, extractor, ejector seem just fine. Basically picture the shell feeding in to the chamber low and impacting rather than going directly into the chamber like normal..have never had this issue before on any of my scatterguns. Usually its double feeds cause of bent shell stops or bad extraction or shortstroke...

August 21, 2011, 02:02 PM	#3
Lee Lapin Senior Member Join Date: September 7, 2004 Location: SE NC Posts: 1,239	Carrier dog spring and/or plunger might be sticky - see Part #6 at http://www.urban-armory.com/diagrams/rem870.htm . Pull your trigger plate assembly and give the carrier dog spring and plunger a drop of lube and see if that helps... lpl __________________ Mindset - Skillset - Toolset. In that order! Attitude and skill will get you through times of no gear, better than gear will get you through times of no attitude and no skill.

August 21, 2011, 03:59 PM	#5
Lee Lapin Senior Member Join Date: September 7, 2004 Location: SE NC Posts: 1,239	It could happen, I suppose. On modern 870Ps the carrier dog spring is heavier than on standard 870s, I don't know when they started using the heavier spring though. Hope that fixes it for you, lpl __________________ Mindset - Skillset - Toolset. In that order! Attitude and skill will get you through times of no gear, better than gear will get you through times of no attitude and no skill.

August 23, 2011, 10:41 PM	#8
bamaranger Senior Member Join Date: October 9, 2009 Location: North Alabama Posts: 8,308	carrier dog spring We had several "870 Magnum"'s in the 15-20 yr old range (not Police models) as duty shotguns that exhibited the same failure, the new shell striking the lower lip of the chamber. Clean and lubed did not really help. Carrier dog spring HD did the trick.

August 20, 2011, 10:40 PM	#2
Ridge_Runner_5 Senior Member Join Date: February 8, 2008 Location: Denver, CO Posts: 1,925	Might want to check the end of your mag tube for debris or rough spots. Lightly oil the inside of the tube near the receiver.

August 21, 2011, 03:36 PM	#4
colostomyclown Senior Member Join Date: February 22, 2009 Posts: 613	Lee, since I'm converting to Flextab capability and swapping these parts out I'll probably just replace the spring at the same time. Based on the issue and what youve said, really this seems like the only possible variable. If that springs bad or gunked up the carrier will be pretty lifeless. It's a 30 year old gun and has probably never been swapped out and I'm inclined to believe it was bad because it was spotless and well oiled when the issue was occurring. Strangely, the gun started off functioning perfectly and worked its way into acting like this. Maybe the spring went bad right then and there..

August 21, 2011, 04:29 PM	#6
colostomyclown Senior Member Join Date: February 22, 2009 Posts: 613	Thanks! A little disclaimer for everyone reading the thread - this is a 30 year old gun. The issue's probably a minor one. Once it's fixed, I'd bet my life on this gun many times over. The all steel construction of the older 870s and 870ps are really a thing of beauty. This gun is smoother than polished glass, it really is a joy to shoot and handle.

August 21, 2011, 04:35 PM	#7
chack Junior member Join Date: May 24, 2011 Location: dixie Posts: 477	I wonder if the magazine spring in it is a standard length spring instead of one for an extended mag.