Model 41 Barrel Fit

Onomea

Onomea

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Earlier this year I bought a 1963 M41 Heavy Barrel. A bit later, I bought an additional 7" barrel. Did not try the long barrel until a couple of days ago. When I did try it, I soon noticed the fit was not quite right.

With 5" HB:



With 7" long barrel:




Fit issues:



I first realized something was up when I could not engage the safety.

I am guessing some sort of modification here is required:



The other possibility that occurs to me is that I need an early long barrel, 7 3/8". These were phased out in the 70s, from my reading. The 7" shown here is after the phase out.

What do you guys think?
 
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I see the very front end of the slide extending past the "dust cover" part of the frame with the 5" barrel and flush with the dust cover with the 7" barrel. This would indicate the slide is being held back slightly. Is the extractor setting properly in its notch in the 7" barrel? Can you see light between the barrel and slide were they meet at the breech?
 
Mike, I think you figured out the issue:

Extractor and notch with 7" bbl



Daylight:



Notch pics:







armorer951, thanks for the tip. They may well be useful to me.

So the solution is to increase the size of the notch sufficiently to allow the extractor to insert itself? Or, is it to modify the extractor so that it fits?

Here's the extractor and notch with the HB:



Thanks for the advice, guys.

It occurred to me try to push up on the extractor with a toothpick to see if that would help it sufficiently to clear the notch entry. It did.



Added a drop of oil. Was feeling very good about it, thought the problem was solved, until I realized the safety could still not push into its notch...
 
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Your slide is not closing up all the way forward with the barrel. It is not the location you circled since the barrel is able to be locked back into place. You are very close, see below.

I too bought an extra barrel and had the Exact same issue.

Measure your original barrel thickness like I show in picture one in several places from rear to front. Now measure your new barrel the same way and more than likely you will find it is wider than the stock one in the forward most location. We are talking .001 or so here. See picture two for the area I am talking about.

Now measure your slide width in several locations as well as shown in picture 3. New barrel most likely has a very slight interference not allowing the slide to fully close.

To confirm the location of the rub, use a magic marker or dykem on the barrel sides, reassemble gun, and gently moved the slide back and forth pushing just a little forward. Take barrel off and look where the rub interference is occurring or starting to.

I used a precision parallel block and bonded 800 grit paper to one side leaving the top edge clean so as to ride against the barrel edge and gently wet lapped (oil) the sides of the barrel (both sides) on the surface I point to in picture 2.

It took me a couple of hours and I had it fitting perfect. Sneak up on it! Lap a little, dykem, try the fit, and so forth. My gun and new barrel is laser accurate with that red dot too. ONLY work on the new barrel, do not touch your slide! If your not comfortable doing any of this please take to a competent gunsmith and show him what I wrote and your issue.
 

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Mike, thanks very much for that explanation. I think I'll look for a gunsmith. It is very helpful to have the problem defined.
 
Onomea said:
Mike, thanks very much for that explanation. I think I'll look for a gunsmith. It is very helpful to have the problem defined.
Click to expand...

Onomea,
In this case you might actually be better off selling this barrel and purchasing another one. I'd suggest bringing the gun with you to make sure it fits when looking at one.

I am not sure, but it almost looks as though S&W might have changed the spec's somewhere along the line as the fit is more than just a hair off. I don't know that for a fact, buy it's off enough to make me think that. Rather than spending money to make it fit and ending up with a Gunsmithed barrel, trying to find another that fits right away might make sense.

I've got multiple barrels for my M41 but I did bring the gun along when looking to buy them. I have not encountered one that did not fit and that is why I am thinking what I stated above about a change. Either that or someone possibly screwed up while being manufactured. I know most M41 barrels are exchangeable without smithing - or at least that has been my experience thus far.
 
Hard to read pictures, but appears the bbl is not locking/fitting into the frame properly. Surprised the bbl would actually lock in and trigger guard lock up?
Looking at the heavy bbl lockup and the 7" bbl fit, the difference should be obvious. Generally a little fileing in the lock area is required to get a good fit.
 
TOM BECKWITH said:
... Generally a little fileing in the lock area is required to get a good fit.
Click to expand...
Tom, thanks for the comment.

Not that I have any intention of trying this myself, but by "lock area," do you mean here, at a point or points within the circled area?



And, when you say "generally," do you mean this is often an issue when fitting a different bbl to an M41?
 
chief38 said:
Onomea,
In this case you might actually be better off selling this barrel and purchasing another one. I'd suggest bringing the gun with you to make sure it fits when looking at one. ...
Click to expand...
Thanks, Chief, for the knowledgeable advice. Just noticed your post this evening.

Not sure where I would go to actually see a bbl... I buy online, generally. Not adverse to the idea, by any means.
 
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Many years ago I bought a 5 1/2" HB for my Model 41 an A prefix early 70's gun with the7 3/8" compensated barrel and loaded chamber indicator. The HB did Not fit and I brought it back to the dealer I got it from.
The dealer was The Gun Parts Guy, Mike Villeux from Springfield, MA. He looked at the barrel with his naked eye and saw some difference in tolerance and gave me a different barrel even swap.
The replacement barrel did fit and worked like a charm. So I guess the moral of the story is on a tight tolerance precision target gun like the model 41 Don't expect a drop in fit. In addition bringing your gun if/when possible is always a good idea to test fit when shopping for barrels. Btw fwiw any other barrels I've tried on this gun always fit & functioned well.
 
OP here. A couple of days ago it occurred to to me to lightly oil the 7" barrel's slide rails.

It now fits. Safety engages properly.

(And yes, I do feel like an idiot...)



 
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Damn , I was about to say , send that junk to me. Nobody wants a 41 made in 1963. ��
 
Did the same thing recently without the drama. Had a HB with a Burris FF3 on my M41 but wanted a long 7 inch too. They look so cool. Mine went right together with no issues. After firing a few mags worth of HV I removed the long barrel and found my old buffer destroyed. It was overdue for replacing and was hard. I ordered a couple more buffers but haven’t done anymore 41 shooting. Next weekend is a local steel challenge match I’ve started messing with so I’ll try it out then. I shoot 2 guns, a Model 625 Smith .45acp and the M41. As simple as it, 5 hits on 5 plates, it’s tough.
 
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