870 Extraction Problems

How many gunsmiths do you know who manufacture guns? How many auto mechanics do you know who make cars?

While the gun makers do not advocate using hones the good ones finish ream the chambers. Not Remington. Sometimes even old guns have the issue. I said "if better quality is out of the question ". The op has a full case, to me that could mean 5000rnds. It's worth 10 minutes to touch up a barrel rather than throw out a full case. 100 round value pack? Maybe not.

Oh looks like the 5000 round case was someone else. Just reread the op. Maybe better ammo is the way to go

mp510, you haven't done any investigation as to the nature of the problem. That means you will get nothing but guesses. Here is what I would do. Pick up your fired shells - the Herters that do not eject. Insert them into the chamber (barrel off the gun) and make a few notes on what you find. Empty shell hard to pull out with your fingers? Any obvious places you see that it is hanging up?

When steel-base shells came out, lots of guns started having ejection problems. It is no secret that the steel base expands when firing, but does not spring back to the same extent that brass does. So the steel may hang up, where the brass shells don't. The important point is to figure out where it hangs up and that can be done by observation.

Lots of new 870's jam like this also, but the problem is NOT a tight chamber.

WireMan

Your correct - Not a tight chamber - but a rough chamber still having machining marks and not brought to a smoothness that handles the steel based cheap shells well.

The hone is not used to try to increase the size of the chamber. It is simply used to remove machining marks that bite into the shell base . A problem that prevails in the steel based shells because the steel does not retract in size like brass will.

It's not brain surgery here, you use a hone very sparingly. I added oil to make sure the hone would not bite into the chamber and remove any significant amount of metal. Then I finished by lightly to medium polishing .
(very little actual honing time required and mostly at just the rear of the chamber where the base of the shell sits)

As I stated earlier this extraction problem is nearly all shell related. However by doing a light hone and polish you can often make the gun extract the cheap shells. It is a simple way to improve the gun and save money by shooting cheap shells.

With all do respect, I don't think you will find a specific location that causes this problem. It is the overall roughness of the chamber rather than a single spot. Nothing the matter with looking things over close however. And no need (most of the time) to do anything to the chamber if you use better ammo.

From what I've seen Remington and Ruger are both companies that don't seem to think that de burr and polish are worth their time. They sell you a rough block and all the parts to build a nice gun if you have the stones and the hones. I don't understand why we have so many steel base shells now. Was that because the brass and copper prices shot up a few years back? Brass is still the best material for shells IMO.

Sorry about that. I seems my phone decided to make a post on it's own.

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Well said!

There were issues with rough machining marks in the barrel hood, or where the bolt locks into the barrel.

When the gun goes into the ejection cycle the locking bolt is retracted and the bolt with it's one extractor is moved rearward.

What happens is the extractor pushes the shell into the barrel hood catching on the rough causing poor extraction.

Check that area of the barrel, it should be very,very smooth.

I have a 74-75' TB Trap model and the barrel hood is that smooth.

Jaguar, that is rather rare issue compared to the batch of Expresses that got turned out a few years back. An angled engagement surface on the extractor can make that one worse, too. Relative to the Express' chamber issues, the rumor mill says a new employee did not change out the chamber reamer on schedule, but whatever the cause, the result was a bunch of chambers with circular machining marks that indeed grabbed the fired steel bases.
I have several '60s to early 70s Remington and Browning shotguns, and the chambers on all of them are like mirrors, and even the notorious Winchester Universals will cycle, albeit the bases get torn some on extraction. You can look at almost any new repeater and see that the chambers are just not as slick as they used to be. The American lust for cheap as possible does have consequences.

Cleaning and an optimistic attitude will not solve the problem. You don't have a cleaning problem and you don't need a brake hone. Let's get this fixed the old fashioned way by figuring out what is wrong first, then grind and file second. What are the results of the tests I mentioned? So far, it looks like you have not tried brass shells like AA's. That might be the clue I referred to.

Do you have a "star" near the 16 GA stamp? Photos are always good.

WM

My 870 does the same thing with steel ammo, I have polished the snot out of it and measured it with precision tools to make sure it does not have a belled chamber but it does not like steel shells. My extractor is good, in fact it rips the rim right off when I slam it onto a bench to clear it.

This is the order I go in to eliminate rough extraction in 870's:

1. Test fire. (OP has done this, but I am posting from the gunsmith's perspective because as I mentioned previously, I am one.)

2. Hone/polish chamber. Costs nothing but a few minutes time. And, yes Jaguarxk120, I inspect the underside of the barrel extension and polish that, if needed. It rarely is.

3. Test fire. If not fixed, go to 4.

4. Replace extractor, plunger, and spring. These parts are inexpensive and easy to do.

5. Test fire. If not fixed go to 6.

6. Replace ejector. I hate doing them, so I prefer to bypass this and check the barrel first, then follow through 10, then recommend ejector replacement.

7. Test fire. If not fixed proceed to 8.

8. Install another proven barrel and test fire.

9. If this resolves the issue, notify owner the barrel needs to be replaced. If not, go to 11, or back to 6, if not yet done.

10. If owner agrees, install his choice of barrel. Headspace, test fire, done. If not, go to 11. (Or back to 6 if not done yet.)

11. Recommend brass headed ammo only, inform owner steel headed ammo will most likely jam.

I've already stated my preference that all my own guns work with any factory loads, as well as my reloads. YMMV.

My 870 Tactical Magnum shoots the Wally World cheapies without a hiccup.

"No star. The star marking was brought into use in/after 1969. My gun dates to 1955.
I did some tests with the empty Herter's hulls. I didn't feel anything particularly rough. The plastic portion of the hull felt surprisingly loose, except that the head was a bit snugger."

Nothing particularly rough. Set aside the brake hone for now. In the first place we see that this barrel most likely has a 45 degree rim seat. Your new shells have modern 55 degree rims. That is one of the difficulties, but not the whole picture. So, does your barrel have a 45 degree rim seat?

WM

mnr: "As I stated earlier this extraction problem is nearly all shell related. However by doing a light hone and polish you can often make the gun extract the cheap shells. It is a simple way to improve the gun and save money by shooting cheap shells."

Nobody likes a rough chamber or a rough bore. Rough is a relative thing. Metal machining marks either grab the shell and cause problems, or not. Why lose sleep over the fact that you don't have a mirror finish inside your barrel? You see that the OP checked his hulls in the chamber and does not notice any significant problem.

So we are trying to be scientific and find the real problem instead of fixing things that aren't broken. Perhaps looking at rims of the fired shells will tell us something about firing a 55 degree rim in a 45 degree rim seat. Or, there may be nothing there at all, who knows?

Even if there are no clues on the fired rims, it might be worth it to reproduce the problem by cycling the action and letting the gun extract a fired hull. Or, if you prefer to work backwards, hone the chamber and bore to a mirror finish, then see if the problem is solved.

WM

You see that the OP checked his hulls in the chamber and does not notice any significant problem.

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The problem with checking the chamber with a fired hulls is that the empty has had time to cool and contract. That is indicative of the difference between brass bassed ammunition and the steel based ammunition as the time it takes to contract, as well as the size it retracts to.

Take the gun that is locking up just after firing with the cheap ammo, and instead of trying to open the breach right away, let it just sit for a short period of time. The hull will then typicaly extract without a problem.

A polished chamber will give the hot expanded hull base less to grab onto and that helps (not always totaly eliminates) extraction under those conditions.

I had the same problem with a newer 870. I tossed my Remmington Gun Club shells in the trash, and bought a case of federal -- problem solved. Buy a few boxes of expensive shells, shoot them quickly and see if you can replicate the problem. If not, it's the shells.

You are highly unlikely to discover a manufacturing issue in an 60 year old wing master. Honing and polishing will work out any leftover burrs, but so will cycling a few thousand rounds, which I asssume has been done with your gun.

My 870 16 does the same with most of the Herters shells. It ain't the gun. Fire, wait a few seconds for the aluminum head to release then it will eject. Not all of them stick, the second case was a lot better. I use them to shoot rocks so I'm not in a hurry. The 12 gauge shells worked fine. and the sticky ones will run right through when it is 20 degrees or colder out.

Yes, we have observed that some 870's will not eject steel based ammo. Some shooters will choose to use brass ammo and be done with it. But, a simple fix will allow the the 870 to function normally with steel base ammo also. It all depends on what you call good enough.

The fired shells do not cool and contract. Once they are fired, the rim and base remain at the same practical dimensions. That is why I suggested gathering up some fired steel based shells, such as Gun Club, Estate, etc and letting the gun go through its eject cycle. We already know that the fired shells do not bind if pulled out with the fingers. So what could possibly be going on?

Well, I did mention that the rim seats are now different than when this 870 was made. That is a clue. The other clue is to actually look at a fired steel based shell as it sits in the chamber. Take the barrel off and pop the fired case into the chamber. Look carefully at the rim of the case, noting the position of the extractor and any other notable visual clues.

Trying the first 10 things that come to mind to fix any problem might in fact fix some problems. It depends on how you approach it. In the engineering world, it is ironically called "the shotgun approach". Do everything you can think of, and hope for the best.

WM