View Full Version : New 870 Pump Question

April 6, 2008, 04:46 PM
I took my new Remington 870 out to the conservation club today to put a box of ammo through it and see how it worked. (This is my first shotgun I've ever owned other than a 12ga single shot I had when I was twelve.) The problem I had is that sometimes when I pump it is very hard, and sometimes it is just smooth as silk and just slides back. Is there a trick to pumping these guys? The gun is an 12ga Remington 870 Super Mag Wingmaster. I took the entire gun apart and cleaned it inside and out and then left a very thin layer of oil over all the pieces before I reassembled it (I followed the instruction manual). But as far as I can tell I got it back together perfectly. And I shot through 25 rounds with no problems other than the occasional pump was hard to pull (like it was stuck on something)... Did I not push it all the way forward first? Any tricks?


April 6, 2008, 06:30 PM
There are two major causes for this.

What's happening is the shell is sticking in the chamber some of the time.
This causes hard operation some times and when it doesn't stick, easier operation.

The two causes of this are the ammo, (often cheaper ammo) and a fouled chamber.

First, buy a shotgun chamber cleaning tool. This is an over-sized, stiff bristled brush on a short handle, and is used to scrub the chamber of plastic and carbon fouling.

Second, after cleaning the chamber, try a better grade of ammo.

April 6, 2008, 06:55 PM
Well it must be the ammo, because there is no way there was fouling of any kind in the chamber. The gun had never been shot as of this afternoon, and before I shot it for the first time I had took the entire chamber apart and cleaned it before I took it to the range. So I definitely think the ammo is probably the culprate. I did by cheap ammo, so I definitely will try a diferent cartridge in the future. Any other possibilities? Thanks so much!

April 6, 2008, 07:09 PM
When I first got my 870 I ran it with cheap ammo. I had the same problems you're describing. Next time I got different ammo and have never had a problem since.

April 6, 2008, 07:10 PM
and before I shot it for the first time I had took the entire chamber apart and cleaned it before I took it to the range

I question whether you addressed the proper area. You addressed the action, and the chamber is accessed though the action but is part of the barrel. Feel very carefully inside the chamber area of the barrel, as sometimes there is a ridge that needs to be dressed up a bit. Insert a mixxed assortment of empty hulls into the chamber and see if any are snug. You might have a tight chamber.
I would go with cheap fodder as being the problem also.

Scattergun Bob
April 6, 2008, 07:18 PM
Hi Brock,

The previous poster is correct in regard to ammo, somtimes after firing those plastic hulls can seize to the chamber walls.

It also could be that you scattergun is new an a bit sticky, adding a touch of lub to the forarm action bars might help. Note; you need to pull the forarm from the receive to do this right.

If this is a express gun, the paint like finish can feel a little bit gummy, 870"s wear into very slick actions, trust me, keep working that forend, It'll happen.

Hope that helps

Good Luck & Be Safe

April 6, 2008, 07:32 PM
I apologize for my ignorance, I do not know the differences between the chamber/action/etc... simply by their names. However, as soon as I got this gun home I took it completely apart. I removed everything from the gun, the barrel, the trigger assembly, the 'firing pin assembly', the magazine spring, etc... I cleaned everything very well and oiled everything that had metal to metal contact. I was careful not to over lubricate and used simply a thin layer of Rem Oil. And sprayed into the trigger assembly according to the manual. So, the first thing I am gooing to change is my cheap ammo. I hope that fixes it! Are there any recommendations for great shotgun ammo that is good quality but isn't mega expensive? Also, thank you all for such excellent responses!

April 6, 2008, 08:56 PM
Just spent the weekend shooting claybirds with my only fired a few times up until this weekend 870 police magnum and a 26 in remington barrel with full choke tube installed. Had a hard time missing. No problem with AA winchester 12 7 1/2 from walmart. I think they were 7 something a box.

April 6, 2008, 09:24 PM
I have 3 870's. Two Express, and one Wingmaster. While I often hear of people referring to different ammo clearing this issue, and I have no doubt that it may, that is not the real problem. I have shot thousands of round of ammo of all types, form the cheapest crap I can find, to some high dollar slugs and buckshot. I do not have this problem with any of my guns.

The chamber is the part of the barrel that the shell fits into. It is difficult to clean properly. If you are using a standard cleaning rod and a 12 ga brush to clean the bore of the gun, you are not cleaning the chamber at all. You must remove the barrel from the gun, and use a chamber brush as referenced by Dfariswheel. If you cannot find a chamber brush (it is a puzzlement to me that these are somewhat hard to find), you can wrap the 12 ga brush with 0000 steel wool until it is a snug fit in the chamber. Dampen it with Hoppe's #9, and work it in and out of the chamber with a twisting action. Better still, if you have a battery drill, chuck the last section of your cleaning rod, and move it in and out while rotating the drill slowly.

When cleaning pay particular attention to the indentation at the top of the barrel assembly. That is where the bolt locks. If this is not perfectly clean, the bolt locking lug can stick and also cause this problem. After cleaning the chamber, and the locking bolt recess, I would recommend firing a box of heavy loads, i.e. full power 00 buck or slugs. This will help "seat things in", if you will

As a simple test, fire your gun without touching the forend. The chamber should open. On a very well broken in 870, it will often eject the round just like a semi auto will. If it stays closed, you still have some issues.

Finally, I recommend this excellent description of properly and thoroughly cleaning an 870 from another forum. Cleaning 101. (http://thehighroad.org/showthread.php?t=17035&highlight=cleaning+101)

Hope this helps. At the end of the day, the 870 likes nothing better than being shot. It actually improves the more you shoot and exercise it. I seriously doubt that you can wear it out even with a determined effort.

April 6, 2008, 09:39 PM
Roscoe, do you think the chamber on a brand new 870 that has been cleaned by hand, but never been shot is dirty enough to cause this sticking?

April 6, 2008, 11:42 PM
No, not dirty, but full of the brown goo that Remington likes to swab on everything. This stuff is sticky, and even a box or two of ammo could leave enough residue to cause problems. Also, as I stated, without proper technique, the chamber is not being cleaned at all, so is likely full of sticky Remington goo. Just my thoughts. Could be right could be wrong. If it were mine, I would thoroughly clean the chamber. In point of fact, I do every time I clean the bore.

As an aside, a friend of mine just bought a little used 11-87. The former owner obviously had not cleaned before shooting it...or after for that matter. Still had lots of brown residue in the bore, chamber and action. A thorough cleaning has it working like new.

Garand Illusion
April 7, 2008, 01:13 AM
Just another +1 that if it is the action ... it will smooth out over time. The first time I took my 870 out it seemed like I had to fight the pump sometimes.

But now that I've been through a mere 250 rounds and 3 thorough cleanings and oilings, the action has REALLY smoothed out. Didn't take long.

I do leave this shotgun a little more wet than I do some other guns I own.

The warning about the chamber stuff is good advice. Thanks!

April 7, 2008, 05:39 AM
The Express version of the 870 have a bit of a rep for having rough chambers.
I would really recommend a bit of time with some 4/0 steel wool wrapped around a bore brush with lots of oil and a good five to ten minute spin with a power drill. It won't hurt the chamber and at the very least it should clean any excess grease/dirt that might be in there.

April 7, 2008, 07:41 AM
I'll go and reclean the chamber and hope that helps! Thanks a lot for the advice about the chamber needing to be cleaned very thoroughly...

I appreciate it very much!

April 7, 2008, 01:33 PM
I've had the cheap aluminum base shells stick a little in an 870 and my 11-87... firing better ammo resulted in smoother operation. That said, if it's brand new, tearing it down and getting that shipping grease (brown stuff) out of the barrel and chamber, along with a little break-free or rem oil on the moving parts should smooth it right out. My brother's 870 Express is smooth as silk (brand new X-mas gift), just cleaned the chamber, barrel and action before I wrapped it up for him.

April 7, 2008, 06:02 PM
My 870 was a little stiff out of the box. But a bucket of shells was all it took to break it in, and it's smooth now.