SW-41 Stove piping

First topic message reminder :

I recently purchased a gently used SW41 pistol. It shoots well but will stove pipe an empty case about every 30-40 shots. Is this an inherent problem with the SW41 or am I just lucky :-D 

What could I do to fix it? I have already cleaned the bolt face well to remove any carbon and dirt. Do I need to change the recoil spring or have the extractor worked on in some way?

Thanks,

-T

I use one drop of oil on the first cartridge following cleaning the chamber. Seems like if I do not use that one drop following cleaning, I will often get a failure to extract or eject on the first one or two rounds fired.

Not a failure every time, but enough that I tied it to a clean chamber I suspect that failure is the result of a clean, dry chamber and the brass simply hangs up just enough to mess with the process.

No problem extracting/ejecting and no oil applied to cartridges at any other time. This is with a High Standard Victor with a reasonably tight chamber.

TAB

kc.crawford.7 wrote:Is the bolt loose in the slide?

 I just learned what a good question this was.   I asked a nationally known gunsmith the question "what parts wear out on a M41" and the first answer was the extractor spring. That surprised me as I expected "extractor", but nope, extractor spring. If the spring is weak, the extractor is not pushing the case hard against the opposite side of the bolt face. That will cause inconsistent extraction patterns.

But also, a loose bolt in the slide will also cause periodic stove pipes. I did not know the bolt would get loose in the slide, and I don't know how loose it has to be,  but the cure for a loose bolt is a light peening of the splines to make it rock solid in the slide. If that is the cure, I guess a little looseness is bad. If the bolt is loose in the slide apparently the bolt face is shifting and the cartridge is also held loosely, or off axis, whatever.

So for those experiencing periodic stove pipes, this is a failure mode and should be investigated as a possible cause.

+1 for cleaning and oil drop trick, but with a catch.  My 41 likes to be worked in after a cleaning, will stovepipe a lot for about 20-30 rounds after a good cleaning.  If I do the drop of oil on the first round (I put it on after I put the magazine in for a string) I have no problems regardless of temperature.

I have 5 recoil springs for mine, can't remember which is in there because the testing process drove me nuts and when it started working well I just left it alone.  Pretty sure I even started setting the gun down on the bench a little softer so nothing changed!

My 41 also hates all ammo with "Match" or "Target" remotely associated with it.  CCI is my go to, but I have not had problems with the federal bulk pack ammo either.

My 1958 vintage 41 was constantly jamming way too often. I sent it to S&W and they replaced the bolt and extractor.  Worked OK for a while, but still not good enough for competition. 

Later, I sent my 41 to Clark for a "reliability package".  When I got it back, it still stove piped but not as often.  I expected better for $250 from a well renowned outfit like Clark Custom.  So I ran a flex hone into the chamber and sharpened the extractor claw.  Now it runs quite well.

My 41 seems to eat SV CCI without the oil drop trick, but I have changed all the parts mentioned.

Try the plop test.  Take the barrel off and hold it vertical and see if you can drop a round in the chamber and it should bottom out and make a plop sound.  Then turn the barrel over and the round should fall out.  If you cannot do this then the barrel chamber is dirty with carbon or a lead ring at the lead.  Clean it until you can do this.  You might need to lightly open up the chamber as well.

Take a look at rimfirecentral - S&W - Model 41 forum.  There is some good information there as well.

Aprilian wrote:drop of oil (with CCI, Eley or SK), so I am curious what does it specifically do?.

My guess is it creates a hydrostatic, and/or dynamic, bearing between the case and chamber. Water might do the same. But the thought of spitting on a gun to get it to work suggests it should just be spit on and tossed aside ;-)

I don't see how it would lube the bottom of the slide, since it's being pushed ahead of the slide. But maybe if you're inserting a mag with the slide closed. Or its getting what ran down onto the next rd.

I found it amazing how many rds (150+) of SK or Eley mine would run without a hitch, even limp wristing it, and how few shots (roughly 3) from a mag of SV would jam it immediately afterwards.

Aprilian wrote:Over on Rimfire Central, there is often a debate about this drop of oil trick which boils down to "a well tuned gun with fresh ammo should cycle without this added lubricant" vs. "Clark advises it for their barrels, so they must know what they are doing".

If everything was perfect we would not need safety belts, or even brakes. Utopia is just one delusion away. And those skeptics about oiling ammunition are just displaying that they know about as much about firearm operation as does a Cargo Cultist knows about airports and airplanes. I just learned of these cults and it is a hoot, if you click on the link, that there is a lot of Cargo Cult Science all over the place. 

I would bet that barely one in a hundred million shooters ever read anything to understand blow back actions and why 22lr ammunition is coated with a lubricant.

This is a great place to start, Vol IV the Machine Gun by Chinn, read the section on blowbacks, first

https://www.ibiblio.org/hyperwar/USN/ref/MG/index.html

Since no one is going to do this,  I would like to address this. American's don't know their firearm history, they are largely ignorant of the mechanisms that required greased, oiled, waxed ammunition to function. Particularly the delayed blow back mechanisms common in the pre WW2 era. These delayed blowbacks were faster, often had less parts, and required pre greased ammunition, pre waxed ammuntion (Pederson rifle)




or had oilers on top. Such as the Japanese Nambu's






This is what Chinn said about ammunition lubrication and the higher pressure blowbacks:




But, humans are capable of infinite self deceit, so the majority, having been presented with something that contradicts their world view, will simple ignore it. People only see what they want to see. So, this won't register at all for many. You will dismiss in an infinite number of ways, maybe that only applies to centerfire, because the laws of the universe are different for rimfires versus centerfires, right? 

Well, Newton's laws of motions apply similarly for rimfires and centerfires. And for a blow back to function, the brass case must not drag in the chamber. Which is why the stuff is coated in a wax, incidentally this is the Pedersen patent, for centerfire ammunition

http://www.google.com/patents/US1780566

Patented Nov. 4, 1930 PATENT OFFICE JOHN DOUGLAS PEDERSEN, OF SPRINGFIELD, MASSACHUSETTS 11,0 Drawing.

In the preparation of cartridges having metal cases for storage and for use, it has been found desirable to apply to said metal case a relatively thin coating of some protective substance which will preserve said metal case for comparatively long periods of time against-deterioration, such as season cracking. In the present invention, the material for said coating has been so chosen as to perform the additional function of acting as a lubricant for the case of the cartridge, both for facilitating introduction into the chamber of the gun and the extraction thereof after firing.  The most suitable wax which I have found for this purpose and which I at present prefer is ceresin, a refined product of ozokerite; but I wish it to be understood that other waxes having similar qualities may exist which might serve equally well.

Some of the desirable features of ceresin are that it is hard and non-tacky at ordinary temperatures having a melting point somewhere between 140 and 176 Fahrenheit. It is smooth and glassy when hard and does not gather dirt or dust. However, when the ceresin on the cartridges is melted in the chamber of a gun, it becomes a lubricant.

Other lubricating waxes have been employed for coating cartridges, and the method most generally pursued for applying said coating to the cartridge case has been to prepare a heated bath of a solution of the wax in a suitable solvent, dip the cartridges therein so that a film of the solution will adhere thereto, and finally withdraw the cartridges to permit the solvent to evaporate from the coating film. This former process is comparatively slow and has been found lacking in several important respects

I am going to say that waxes are not as good lubricants as light oils. In cold weather waxes get much harder than oils and cause function failures, especially as the wax condenses on the interior of the chamber and action during the residual blow back period. Oiling your 22lr ammunition will dissolve that wax, to a certain extent, and even the greases on the better match ammunition, and keep you running longer. In time crud will build up and your 22lr will have to have its chamber cleaned, and probably the feed ramp too. Oiling will not cure all problems, but breaking the friction between case and chamber will enhance extraction. I have had bud's whose Walther's were jamming, got them to oil their 22lr's, and they were happy campers when their pistols started functioning again. You know, damn the dogma of idiots, I believe what I see in the real world.

I don't want to get too deep into this, but the pathological fear of greased and lubricated ammunition goes all the way back to low number M1903's. The Army was building defective 03's in antiquated factories. Factories that did not have temperature gauges. So whenever heat was applied, things were getting over heated. Many low number receivers, bolts, barrels were burnt and blew up during proof, or if they survived proof, blew up in the hands of a user. Incidentally the bullets fouled something awful and shooters were greasing their bullets to prevent cupronickel fouling






At the time, "perfect" Army rifles are blowing up with "perfect" Army ammunition, so the fault much be that grease, right? You believe that don't you?  Perfect Army rifles cannot blow up unless the user was doing something stupid, like greasing their ammunition. Because grease unpredictably, and massively raised combustion pressures, and that was also true of oils.  That was what the Army Ordnance Bureau was telling everyone, and so were those sycophantic authorities in print, and anyone who disagreed was dealt with harshly because that is what is done with dissenters. Would the great and powerful Army lie? Would the benevolent Army knowingly build and issue defective rifles that would blow up and take off a user's face?  Would the all compassionate and caring Army keep defective rifles in service once they were made aware of the dangers? Of course not, right?  You believe and trust authority, and well, because of this, it has become a core belief in the shooting society for over a hundred years, and will probably be that way for much longer


The myth of over lubrication:


https://www.youtube.com/watch?v=p9bOT_d60LM

LenV wrote:The "drop" of oil isn't to add oil in the chamber. It is to oil the bottom of the bolt. If it bothers you to get the oil on the bolt indirectly then add a drop into the magazine well. You can do a much better job by turning the pistol upside down and letting a drop fall onto the bolt. No one seems to have a problem with keeping the action well oiled. There will still be a little oil transfer to the top bullet in the magazine but any well oiled pistol gets a little splatter. 

Len   This was my opinion of course..

Keep oiled

I have two Clark build 41's, the bottom of the bolt has been polished to a bright shine by Clark. In addition I place a small amount of gun grease on that surface. I have not had but one stove pipe since the pistols were returned to me and about 5 cases of ammo has gone through them in that time.

41's seem to be of two types, the ones that continually give their owners fits and the kind that never so much as hiccup.  If oiling the top round works than no reason not to do it.  My 41 is very trouble free, I thought it was because I cleaned it after every trip to the range, I now only clean it every 700 or so rounds and it still gives me no grief.  I suspect the ones that give people fits have any of the problems mentioned or a combination of several of them, throw in ammo issues and they can be a big pain in the backside.  Good luck with your efforts to get yours running.

Don´t know if this is applicable i this case... I guess these are more general observations on .22 semi autos.

However a long time ago a talked about erratic ejection that I was experiencing with my Sako Triace in .22lr with a finnish gentleman, he told me that he had had similar problems that were fixed by a Sako gunsmith at a competition (in Finland, quite a few years ago).
The gunsmith had a conical punch that he used to reverse a very slight peening that had occured in the rear end of the chamber.
He simply popped it in the chamber and applied a hammer to the punch. 

I made one myself and it works for solving that problem.
A chambering reamer or honing the rear of the chamber would have the same effect I imagine.

There is however also a reason to keep the extractor nose sharp and that is so it can hold on to the case properly so that the energy from the ejector is transferred properly into rotational movement outward of the spent case.
The extractor acts as a pivot point is another way to put it...
If its dull the case can slip and fail to eject.
A problem that I have experienced several times with my Pardini SP:s.

As mentioned earlier the extractor spring needs to be in god shape as well. And you can tweak the extractor so it doesn´t hit the bottom of the slot in the barrel and ride outwards when the slide goes home... 

/Anders

TureB wrote:
As mentioned earlier the extractor spring needs to be in god shape as well.
/Anders

It is my opinion that extractor springs wear out sooner than extractors, and that spring tension is critical for proper ejection. The extractor pushes the case against the side of the breech face, if that is weak, the case will pop forward when the ejector hits the rim.