Mk III smokestack jams

charlesb · Post by **charlesb** » Tue Jun 08, 2010 1:49 pm

My Ruger Mk III Hunter gets an average of one smokestack jam per clip, sometimes two.

I have tried five different brands of ammo, but it appears to jam impartially with all brands. None of them seem to be better or worse than the others.

Is there a low budget or preferably no budget fix for this that I can try? I have a machine shop at my disposal so more advanced procedures are not a problem.

I generally clean the pistol after two or three clips, so I do not believe that dirtiness is the problem.

I'm wondering if a bit of polishing here or there might help. The pistol has roughly 400 hundred rounds through it at this point.

It is 100% stock with the exception of a 2X Burris scope. The gun is gratifyingly accurate but the jams are a problem.

blue68f100 · Post by **blue68f100** » Tue Jun 08, 2010 2:43 pm

I assume you are referring to "Stove Pipes". This happens when the spent shell falls off before the bolt goes back far enough to hit the ejector.

You say you clean, do you remove the barrel and detail clean?

Is the slot on the right side of the barrel clean, this is where the extractor rides when the bolt is closed.
Is the bolt and barrel breach faces clean of powder residue?

With the bolt out see if it will hold an empty brass with out falling off. In most cases these are stamped factory parts. Most replace the factory extractor with an Exact edged Extractor from VQ, this is an EDM cut part to a very tight spec. If a new gun and are having these problems the magazine may be riding too high.

Another place to look is the LCI, To test push on the LCI from the inside (metal tab) and see if it springs back unrestricted. If this is gummed up it will cause Stove pipes. To clean you need to remove the barrel to gain access to the pin holding it in. It can be removed with a strong magnet, and some light pressure to unload the pin. Some remove it all together and install a filler pieces. There are several way to disable the LCI but I have found as long as you keep it clean it does not cause problems. To disable you only need to remove the spring that contacts the metal tab. Some remove the metal tab too. Leaving the main body to fill the slot.

This should you started.

charlesb · Post by **charlesb** » Tue Jun 08, 2010 3:41 pm

Thank you for the information, blue68f100! I will disassemble the pistol this evening after my chores are finished and address the areas you mentioned.

My cleaning regimen has been to disassemble the pistol, clean the barrel, then work on the interior of the frame with brake cleaner and a 45 caliber brush on a pistol cleaning rod. I scrub the bolt and bolt face and use brake cleaner there too, then I lube it all up again with dry moly spray and put it back together.

I use the dry moly so as to avoid the mud we get from powder residue mixed with oil.

I'll post here again after I have looked the pistol over more carefully as you suggest, and test fire a few clips through it. It will be tomorrow morning before I can test fire the pistol, so look for a reply then.

blue68f100 · Post by **blue68f100** » Tue Jun 08, 2010 5:38 pm

If you have not been removing the LCI to clean it, it's probably the culprut. It's most often over looked on the MKIII models. Using solvents to the barrel just run into it and gums them up. Easy fix though.

charlesb · Post by **charlesb** » Wed Jun 09, 2010 2:16 pm

I didn't get to look at it last night, we had some company show up but I ought to be able to look it over today.

More later!

HEADKNOCKER · Post by **HEADKNOCKER** » Wed Jun 09, 2010 2:44 pm

I might also suggest a Volquartzen Exact Edge Extractor..
I too think the trouble your having may be rubbish on the LCI..
Good Luck!!

quickslider · Post by **quickslider** » Wed Jun 09, 2010 8:21 pm

I had the same problem with all three of my Mark 3s. There was an article in here somwhere regarding reshaping the magazine. It's a ver simple operation and it works. Everyone I know that has tried it is amazed at such a simple thing. If you ask Bullseye I'm sure he knows where the article is located. I also agree that removing the LCI also helps

charlesb · Post by **charlesb** » Wed Jun 09, 2010 9:47 pm

I tried the test of the extractor with an empty brass with mixed results. Sometimes it held well, and other times it slipped off of the extractor without much resistance. As a test, I tried pulling the extractor out and letting it snap back in place a few times, and it always seemed to return in the same position.

Everything looked pretty clean, in general. I clean the gun often and the brake cleaner spray is very effective. The dry-moly lubricant I use doesn't attract or combine with powder residue, so most of the residue gets blown clear of the action instead of accumulating here and there.

I didn't notice anything unusual about the LCI, it moved easily and was clean.

I'll look into the magazine modification, I remember seeing it in the past, but I forget where.

I tried switching magazines with no change. It gets a smokestack jam once or sometimes twice with each magazine.

On the brighter side, the accuracy is still very impressive. - Either it is more accurate than a scoped S&W model 41 that I used to own, or I am a better shot now than I used to be. That Smith was a real beauty with Conetrol mounts. I sold it to finance another gun buy, twenty years ago.

In any case, I can hit a 1/2" object with the Mk III at thirty feet more often than not, standing up and using a Weaver hold. The 2X Burrus scope is as good as any handgun scope I've used in the past, and is better than most.

If the magazine modification does no good, I'll look into installing a better extractor. This is the pistol's only real drawback so I am looking forward to getting it ironed out.

Thanks to everyone for the great advice and well wishes. - I'll keep at it until it quits jamming.

Even if I don't end up fixing the problem, I intend to keep the gun as it shoots so well.

blue68f100 · Post by **blue68f100** » Wed Jun 09, 2010 10:22 pm

Here is the link for the magazine tweek. This does help on feeding problems but not so much on stove pipes.

http://xavierthoughts.blogspot.com/2008 ... tweak.html

bigfatdave · Post by **bigfatdave** » Thu Jun 10, 2010 7:06 am

Pull the LCI and see if the problems go away, then decide to install the VQ exact edge extractor (really, it is an easy install and the thing costs less than a new mag for the gun)

Staring at a gun on the table doesn't get a lot of troubleshooting accomplished, and that LCI can be lost with no ill effect whatsoever ... so why not see if it is part of the trouble? I really like the mkIII design (if the LCI, mag interlock, and internal lock are ignored) it makes for a very accurate gun and the ergonomics are great without adding silly grips or anything. So get out to your favorite range and start blasting without the LCI riding the rim of every case on the way in and on the way out, and at least eliminate a possible cause of your troubles.

charlesb · Post by **charlesb** » Thu Jun 10, 2010 9:23 pm

I modified one of the magazines, and took it out in the yard for a quick test. It was near dark, and a church nearby was having services so I only shot one magazine's worth. There were no jams.

In the morning, I'll take it to my regular plinking spot with several brands of ammunition and give it a more meaningful test.

The most persnickety ammunition I have is some unplated Winchester T22 target ammo. - I'll bring a box of that along as well. Normally I save the T22 stuff for my Contender, but it'll be a good acid test for the MkIII with the modified magazine.

If nothing else, it will be a good excuse to go out and shoot.

charlesb · Post by **charlesb** » Fri Jun 11, 2010 5:54 pm

Here's a picture of two MkIII magazines. The one in front is modified. I rounded off the edges on the rear set of lips, and polished the upper surface of the front set.

{ Click the image to see it magnified }

The modification appears to have taken care of the problem with smokestack jams. I saved the second magazine for my son to modify, so that he will know how to do it, and have some experience with the procedure.

When doing the mod and later on for the photo, I used a toothpick to hold the follower down and out of the way.

Post by **Bullseye** » Fri Jun 11, 2010 7:40 pm

How's the mag positioning? http://www.guntalk-online.com/forum/viewtopic.php?t=18

R,
Bullseye

charlesb · Post by **charlesb** » Fri Jun 11, 2010 8:13 pm

It looks very similar to the one pictured in your article, except mine isn't clean, it's had thirty rounds cycled through it since the last cleaning.

Does it look OK to you? I may need to take another picture, as the camera flash created a shadow from the extractor that obscures the ejector a bit.

Post by **Bullseye** » Sat Jun 12, 2010 5:52 am

Yes, it looks fine. I can clearly see a gap between the rear feed lip and the ejector pin. If the two were touching, that could also cause the problem you described. What would happen is the rear magazine lip would jar loose the spent case before it struck the ejector pin causing the stovepipe jam. Based on what I see, if your pistol is still experiencing jams then look to the LCI or the extractor claw. You can remove the LCI and test the pistol. If your pistol runs flawlessly without it then there's your cause. If not, buy a VQ exact edge extractor and replace the factory one.

R,
Bullseye