M-41 Clark Barrel Relief?

Mountain Man · Post by **Mountain Man** » Mon Dec 05, 2011 7:39 pm

I have a Clark STC barrel. On my newer Mod 41, it is somewhat harder to close the trigger guard onto the Clark barrel than the stock barrel. On my recently acquired older (1971) Mod 41, it is very difficult to close the trigger guard onto the Clark Barrel. I am grasping the barrel with finger tips of both hands and pushing with both thumbs. I am concerned that I may damage the gun.

The barrel seats well onto the frame and functions well on the range so, I assume that the "foot" is in the right place. Should I relieve the pressure on closure by stoning away some of the back notch (pointed to in the pic below) or is that the wrong way to fix this??

jstanfield103 · Post by **jstanfield103** » Mon Dec 05, 2011 8:12 pm

Have you contacted Clark yet? I bet they would tell you exactly what needs to be.
Or maybe Bullseye will be along soon to give his advice.

Mountain Man · Post by **Mountain Man** » Tue Dec 06, 2011 7:46 pm

It has been my experience that you are well served to know as much as you can before you call a tech support service. It helps to focus your questions and to evaluate the answers.

Python · Post by **Python** » Tue Dec 06, 2011 7:55 pm

I have the same barrel except the 6.5"
Would have to say that it closes in my M41 about 30% harder than the original barrel.
No problems so far.
My thought is the better it clamps the better it is.
I use the heal of my palm to close it by pressing my hands together, the left hand holds the pistol and my right palm pushes it shut.

Clarence

Post by **Bullseye** » Wed Dec 07, 2011 6:34 am

There can be a barrel fitment issue between new replacement M-41 barrels and some of the older frames. Where the trigger guard must be forced to close and lock onto the barrel with far greater effort than with a properly fitted barrel. This often feels as if the trigger guard pin will shear from the application of extra pressure. Generally this condition centers around the barrel cam lock and the lug in the bottom of the barrel. Your picture indicates the correct area but proper fitting is a little more involved than the average home tinkerer can typically achieve. Basically, you need to have the barrel firmly held square in a vise so that a file can carefully be applied to the "birdsmouth" cut on the back side of the mounting lug. However, you only want to remove material from the bottom surface and not the top of the angled cut and you do not want to change the angle of the metal. This will require a safe edged file. Also if too much material is removed from the lower flat surface, or if any metal is removed from the top surface, a loose barrel fit can occur, causing possible reliability issues.

It is up to you to carefully evaluate you skills before taking on a project like this one. If you choose to fit your barrel, go slowly with the file and check often for fit. It will take very little metal removal to have a major change in the barrel fit tightness. Check for proper fitment every couple of strokes with the file. Eight or ten strokes is likely all it will take to do the job, but it must be done precisely or a loose barrel fit may be the result.

Since this is a Clark replacement barrel you may wish to contact them about the fit issue. They may offer to fit your barrel to the frame for you. Smith can fit your barrel for a reasonable fee but since it is an aftermarket barrel and not one of their own, they may be reluctant to offer this service.

Hope this helps.

R,
Bullseye

Mountain Man · Post by **Mountain Man** » Wed Dec 07, 2011 5:38 pm

Bullseye wrote: Hope this helps.

R,
Bullseye

WOW! Yes, it really helps!

I called Clark earlier today. A lady answered and when I told her I needed some tech help with one of their barrels, she said she could help. Uh, oh! Hate to be chauvinist but, you know! Listening to my description of the problem, she said "You are going to have to file the barrel!" I said, "Where and with what?" She said, "With a triangular file and you want to file the bottom of the notch. You should draw the file towards you once or twice and test it." I heard a voice behind her and she said that "He said you should file both sides evenly but I always thought it was the bottom only."

Then she offered to consult the gunsmith and send me an email. I asked that she get the exact size and model of the recommended file. When the email arrived, it had this pic along with a link to a file model description:

So, I went shopping for the file - found it locally! - and hoped that Bullseye would answer and help me out of this dilemma of which surface to file. He did! And, the lady was right! For me, it all depended on how the cam lock works - if it pulls down, I need to file the bottom. If it pushes straight ahead, I need to file both surfaces. Sounds like it pulls down.

There remains the issue of "pulling the file." The file they directed me to is a "single cut" file. Pulling it should have little effect??

And, the question on the table now is whether I can achieve one single barrel to fit both a new Mod 41 and a 1971 Mod 41?? I have to be very careful that making it fit the older 41 doesn't make it loose on the new one.

Sorry to be so verbose - lots of issues! And, thanks again, Bullseye and I hope you find time to read this!

Post by **Bullseye** » Wed Dec 07, 2011 6:35 pm

I'm so sorry that I wasn't able to answer your question sooner. I have been extremely busy lately. However, I see that you are more than satisfied with the responses you received from both myself and Clark Custom. That edge that is depicted with the black arrow is exactly what I was referring to in my description. I use a safe edged file for this task but a triangular one would do just fine. The main thing is you only want to file one surface at a time. Accidentally filing two surfaces can have catastrophic results for your barrel's fit. Since I'll assume you don't have any Dykem metal marking compound on-hand you can use a Sharpie permanent magic marker as an alternate to coat the metal. Give it a few minutes to dry before attempting any cuts with the file, this way as you file you can see that you're cutting evenly on the surface. Now since you want to fit this barrel for two pistols you'll have to check the fitment on the other frame. If the barrel fits with out any undue stress placed on the trigger guard then you may have a problem. But if both pistols require some extra force to close the guard, but one is less than the other, then you may have to find a happy medium between the two frames as far as trigger guard tension. Otherwise you may end up with a loose barrel on one and not on the other essentially making it a one frame accessory. Be sure to check fit often as you cut the lug. Stroke the file in the direction of the cut and lift it to return, this will keep the file from filling up with shavings and hindering the cutting ability of the file. Smooth slow strokes with even pressure will do the task. Try practicing on a scrap piece of metal before attempting any cuts on your new barrel lug.

Hope this helps.

R,
Bullseye

Mountain Man · Post by **Mountain Man** » Wed Dec 07, 2011 8:52 pm

Bullseye wrote:...clipped... The main thing is you only want to file one surface at a time. Accidentally filing two surfaces can have catastrophic results for your barrel's fit....clipped

Hope this helps.

R,
Bullseye

Just great! And, I really appreciate you time and advice. The quoted portion is all that confuses me - I thought that I was only going to be filing the one bottom surface???

Post by **Bullseye** » Thu Dec 08, 2011 5:26 am

You should have copied the sentence before too. That is where I mentioned only filing one surface. What my point was - you don't want to use a regular square file with no safe sides because there's a high possibility that you would accidentally file more than one surface while only focusing on one particular part thereby causing a fit problem. Just work the single surface and use the marker frequently to check the filed cut for squareness and evenness as you go. It really shouldn't take very many file strokes to get the right fit. You want some tension on the trigger guard but only on the last few centimeters of its travel; like the original factory barrel has when you close the trigger guard.

R,
Bullseye

blue68f100 · Post by **blue68f100** » Thu Dec 08, 2011 8:42 am

By the looks of it you may be able to measure the thickness of that area against the back cut. It will give you an idea of how much material will be removed.

Measure twice cut once like they say, so go very slow. Once removed you can not put it back.......

Good Luck

Mountain Man · Post by **Mountain Man** » Thu Dec 08, 2011 8:44 am

GOTCHA! Thanks again!

Mountain Man · Post by **Mountain Man** » Sat Dec 10, 2011 8:12 pm

Well, I did it! Wasn't as hard as I expected but, I had plenty of room to correct errors. It took much more filing than I thought it would to relieve the pressure. It's still tight but acceptable. I don't want to go any further until I have the other 41 back from S&W to see how the barrel fits it.

Post by **Bullseye** » Sun Dec 11, 2011 7:48 am

Great! Sounds like you took your time and made small cuts to adjust the barrel lug. You made the right choice to check the fit on the other pistol when it returns.

R,
Bullseye