Remington 870 Extraction problems - it is not the chamber.

[oldguy870]

I have 6 Remington 870 with a total of 8 factory barrels:

(4) Express guns with factory 18.5" police barrels
(1) Wingmaster with factory 28" barrel and factory defense barrel.
(1) Express with factory 18.5" barrel and factory 26" barrel.

Every single one has problems with Federal Walmart steel hulled ammo. These same guns run perfect with Winchester AA brass based shells. Three of the barrels have had the chambers recut and polished by a Remington repair center. I have done the AIPPI steel wool polish multiple times to each.

ALL STICK HAVE EXTRACTION PROBLEMS with steel hulled shells. Some barrels are worse than others. Typical failure rates are 5% to 25% depending on the barrel. My Benellis eat this ammo like candy.

I read the following post and did what the author recommended to all my barrels. The problem is solved. No extraction problems. Basically, the fools at Remington don't seem to mind shipping barrels with toolmarks that the steel rim catches on outside the chamber when it expands after firing. If you have a 870 with extraction problems, take a look at the ridges just outside the chamber. Steel shelled hull expanding into a steel barrel with ridges = stuck shell.

It is not the chamber. It is outside the chamber. Here is a post that explains the fix. It is not my post. I just did what it said and the problem was solved.

http://www.shotgunworld.com/bbs/vie...&sid=116973b1f9895985ccaf1b7ff4d3ad88&start=0

 

[AI&P Tactical]

The issue people have is extraction. Getting the shell out of the chamber. Once it comes out there is no issue so the area the guy shows in his pictures have nothing to do with this as that area is so much larger then the chamber. Don't even understand his point. I could be missing something so someone explain it to me better then he did on Shotgun World as that post makes no sence to me. I am an old Dog but can learn new tricks so I am listening.

 

[Virginian]

I have seen that "fix" as well, but it merely left me baffled.

 

[Miked7762]

Due to the way shells are manufactured the same pressure that expands the base will also expand the rim. Most of the extraction problems are caused by the base expanding into the rough machining of the chamber. What he is saying is that the rim is expanding into rough machining immediately OUTSIDE the chamber where the rim headspaces.

Is it really happening? If someone has a barrel with a polished chamber that still locks up on these shells, it would be easy enough to check. The rims of stuck shells should be fairly mangled on the side that hits the ejector. A little prussian blue on the area behind the chamber would also show how deeply the rim is expanding into the machining.

 

[Virginian]

The rim has a much different shape and two layers of metal to resist deforming. Just about anything is always possible, but I have never see anything close to what is described personally. Every sticky extraction issue I have seen has been a rough/dirty chamber or a faulty extractor. If one is having issues, I guess this is something else to check, but it would be last on my list.

 

[oldguy870]

"What he is saying is that the rim is expanding into rough machining immediately OUTSIDE the chamber where the rim headspaces."

Exactly.

On most of my barrels, this area has so many tool marks parallel to each other, they look like the rings of Jupiter. I agree that it makes no sense to polish the entire area in the pictures. However, polishing the rough areas outside the chamber where the rim headspaces is the key.

After having 3 chambers recut and doing Aippis steel wool thing over two dozen times, I am convinced the chamber is not the issue.

The results from cleaning up this area are the proof. No more extraction problems.

P.S. If my Benelli can run Federal Walmart ammo by the thousands without a malfunction, a pump gun should be able to. That is supposed to be one of the benefits of a pump gun - they can run anything.

 

[chas08]

Could it possibly be the extractor is just pushing the rim over far enough as the hull leaves the chamber that it is catching on the machine marks?

No fault of the extractor. It's spring is just providing the force that makes the shell rim dig in.

 

[oldguy870]

My guess is that there is not enough force that could be generated by the extractor compared to how tight these actions lock up.

I think it is the expanding steel hulls getting wedged in tight to the steel tool marks on the barrel. Steel on steel.

 

[AI&P Tactical]

I'll keep an open mind. However, the base expanding I get. The rim expanding I don't get. I Use Winchester Universal Bulk ammo to test fire my custom builds and any weapon I rebuild or any repair. I have zero extraction issues because I test the chambers. I have over 300 barrels in stock, 870, 1100, 1187 in both 12 and 20 ga. I went out and looked at the barrel roots of about 20 different factory new barrels for this type of damage and found none. I did see some light markings but they are not pronounce enough to cause such an issue. I think a camera picutre of them would make them look like the Grand Canyon. However, even if the rim swelled as stated, it would be easily pulled over those light marks as they are not deep enough to cause an issue.

I will continue to look for this and if I find a barrel with any such issue and see this condition I will try to polish it like the OP recommends. Can't hurt, and anything that assures perfect extraction is worth a couple extra minutes.

 

[oldguy870]

AIP, one of my barrels with this problem is a Wingmaster home defense barrel. I bought it from you.

I am not blaming you. It is Remington. I am not an 870 hater either. If I didn't love the 870 so much, I would have sold these problematic things a long time ago and stuck with my Benellis.

My worst 870 locked up 4 times during a 3 gun match using Federal Walmart ammo about one month ago. It had had the chamber recut and the steel wool thing done multiple times. As my last hope, I polished the outside of the chamber last weekend and ran 100 rounds of Federal through the gun. NO PROBLEMS.

P.S. For what it is worth, I have never had a single extraction problem with brass based shells.

 

[Virginian]

Well, I have fixed about a dozen 870s and a few others with extraction issues by honing the inside of the chambers, nothing more. But, I will keep an eye open for this in the future.

 

[DNS]

What is the technical term for the extended part of the barrel that we're talking about?

I'm gonna check to see if there are tool marks on some of my barrels.

 

[rbernie]

Barrel extension.