870 feed probs

B

bamaranger

New member
I have an issued Rem 870 that exhibits a failure to feed on a regular basis.

When pumped rapidly, it appears that the "lifter" raising the shell from the mag tube to the chamber mouth, does not align or raise properly, and the fresh shell ends up ramming into the lip of the chamber mouth.

I'd like to say that the round is hitting the top of the chamber, but cannot for sure.

My impression is the "lifter" is slow, and the bolt, coming forward, picks the round up before it is fully raised. The round then jumps into the chamber mouth and gets tied up at an odd angle.

If the gun is run slowly, this seems not to happen. If the gun is lubed to the dripping point, it seems not to happen.

I am an experienced shooter and am not short stroking the gun. The gun is CLEAN and lubed, though stowage in a LE vehicle 24/7 in summer dries it out quickly it seems.

The gun is stamped 870 mag and is parkerized. It is about 10-15 years old. It is not a Police Mag.I have heard that there are factory parts that enhance function that are installed on the Police Mags.

What is going on here and can I buy factory parts that will enhance function and "upgrade" this gun to Police Mag stds.
 
self diagnosis

I discovered the search function on this forum and searched Police Magnum!

The part that I now suspect as being weak or worn is the "Carrier Dog Plunger
Spring" which drives the "Shell Carrier". If the shell carrier would operate in a more positive fashion, I believe the gun would feed more reliably. Supposedly, the Police Mags have heavy duty versions of this spring, and I will attempt to obtain same. I already have a line on a certified armorer to install same.

Anybody else experience this problem and apply this fix?????
 
one mistake at a time

Well........

In checking a parts list in BROWNElls, there are no Police parts, and there is no "carrier dog plunger spring" . There is a "carrier dog follower spring".

At this point I need a schematic and more of a clue. I am going to bend the certified armorer's ear tomorrow.

The armorer may have access on the "police" parts.
 
bamaranger

Wow, a real 870 repair question:).

What you are describing and we are all searching for is a condition called "fails to feed up". I published a short fix-it manual about 2 years ago titled "870 Express upgrades. Might be worth searching for it. below is the relevant passage for "feed up" problems.

Carrier Dog Follower Spring – I have noticed in many worn models a problem with the action hanging or stuttering on the closing stroke (fail to feed up), this is commonly caused by the shell carrier not traveling high enough into the receiver and the shell hanging up on the bottom of the chamber. It is a common occurrence and is usually fixed by replacing with P/N 16966 a heavier version of the follower spring, Do Not change if you are not experiencing this problem, it could create a new one.
Click to expand...

Of-course without the scattergun in my hands I can only guess, however a pooped-out carrier dog follower spring can do what you describe. That said the action bars out of line, the shell latches too sloppy or too sharp of a lower corner of the extractor can also cause this condition.

bamaranger, I am a little concerned that you are considering doing this repair, if this is a department issue gun, then I suggest that you let the person who has his backside responsible for the liability of the weapon do the work. As a armorer for a large department, had any of my troops engaged in repairs of the guns I was responsible for, several motivational lectures would have occured ;).

Best of luck, and be safe.
 
SMM why do you say to get the 1100 version?Do you think it has some advantage over the one for the 870?It would be very strange if it did since they are both pulled from the bin that is labeled part#17415.
 
SMM why do you say to get the 1100 version?Do you think it has some advantage over the one for the 870?It would be very strange if it did since they are both pulled from the bin that is labeled part#17415.
Click to expand...

You are right, as they are the same spring. That the 870P and the 1100 use the same spring is just an interesting little fact I picked up on another board. Makes you wonder why it is not used in all of the 870s, doesn't it?
 
The 870(Express and Wingmaster) and the 1100 use the same spring.

The 870P spring is a different part number.(stronger)

The 870 Marine Magnum is yet another part number.(plated)
 
update

THanks for all replies. Yeah, it is an "issue gun". Its never really been right either, balking on the rapid fire section of our agency shotgun course. Normally, since its for score, you just muck through it, jack the pump a bit and the stubborn, offending round , chambers and you go on. Recently, I got tired of it, and decided to follow up. Darn, shouldn't a manually operated firearm be 100 % reliable, or nearly so?????

We do have a dept 870 armorer, and I am going to get the gun to him soon. He's recently been to the 870 refresher as well. Sorry to say, I have limited faith in him though. Therefore, I am trying to get an understanding of the problem and repair for my own satisfaction and possibly as a "guide" for the fellow.

Though I have handgun sig and Colt m16 armorer certs, and am the typical hobby tinkerer, I am NOT tearing into all those pins and springs in an 870 trigger group, and NOt w/ Uncle's gun. Thanks for reinforcing that.

I am going to try a second trigger group, likely from my personal vintage Wingmaster. Also, we have several "spare" 870s about, and I may be able to borrow a trigger group from one of those as a test.

I'll keep y'all posted.
 
The 870(Express and Wingmaster) and the 1100 use the same spring.

The 870P spring is a different part number.(stronger)

The 870 Marine Magnum is yet another part number.(plated)
Click to expand...

I thought we just agreed that the 1100 uses the same spring as the 870P:confused:

I have been advised of this by an 870 armorer.


It does after all have the same part number in the Remington parts list as the 870 "heavy" carrier dog follower spring (which is the spring used n the 870P).
 
You are confused
Click to expand...

Partially at least.

There are only three carrier dog follower springs in the Remington parts list. One is for the 870 Marine Mag. One is for the 1187 Super Mag. The other is listed for the 870, 1100, and 1187. It is described as "Heavy".

That means one of three things:
1) The 870P uses a non-catalog spring which is unlikely given that every other Police part is in the catalog.
2) The 870P uses the 1187 Super Mag spring (which I assume would have to be heavier to deal with an auto loader and 3.5" magnums). However, wouldn't they list in the 870 section along with Police in the description if that were the case?
3) The 870P uses the same spring as the 1100 (and 1187) and the Express and Wingmaster now also use the "heavy" Police/auto loader spring.

I think 3 is the most likely as I have heard time and again that the list of differences on the Remington website regarding the Police model vs regular is out of date. At one point a standard spring existed apparently and they came to their senses and stopped making it. I can't imagine them reverting from the heavy spring to the regular spring.
 
StuntManMike

Mike,

You are correct the original "heavy" spring used in police models of the 870 and as a repair for failures, was standardized into P/N 17415 according to the LE rep at the factory. I called him today because of all the confusion. All 870's use the same weight spring. That said, the above P/N should solve the feed up problem created by a weakened carrier dog follower spring.

Good Luck & Be Safe
 
now that is interesting

I just went to Sarge's link and looked at the advice there..

What is interesting is that this was the first comment my armorer made, ie: "maybe we should bend the shell carrier lip". This is starting to sound like a factory recommendation. Yikes!

Seeing as I don't really want to go warping on factory parts, I'll pursuit the spring change, then consider the carrier mod as a last resort.

Hey, I just did a quick check of the carrier lips: the agency gun v. my personal old reliable yields a very similar configuration. Ol faithful does have a bit more trough, but its VERY subtle, not a flat duckbill by any means. Interestingly, there does indeed seem to be a small "tweak" on each, as if performed w/ padded pliers. I wonder, could this be a factory "fitting" process after assembly or a function "adjustment" at an inspection station?????

Lastly, I removed the trigger group, and , in sliding a live round up the carrier, by hand, the U-shaped slot/tab on the newer, agency gun has a tendency to hang the leading edge of the brass on the shells. I mean like noticeably. Old reliable has no such Ushaped slot/tab and the shells slide readily. What is the purpose of the slot, some type of antijam gadget I'm thinking? Would it hurt to bend the tab outboard a small bit.
 
Thanks for the update SB,I marked the 870P spring out in my Numrich catalog and made I note as to the changes.Now I ain't confused anymore,sorry about the wrong info stuntman.
 
bamaranger

The U shaped cut in the 870 shell carrier is called a Flex Tab system. It is the fix for a common feeding problem in the gun. Here is a vid on how it works http://www.youtube.com/watch?v=dHHOYwco9xE . The tab should be in near perfect alignment with the carrier and my need an adjustment. I do not recommend "bending" the carrier lips.

Good Luck & Be Safe
 
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