Gunsmithing Odd 22lr barrel mod.

[gunnergirl81]

A friend of a co-worker wanted to get his Marlin 22 bolt gun's barrel shortened and the muzzle threaded. So he brought the rifle over for us to take a look. Its a model 25, like one we have, but it has a heavy barrel.

Now, here's where it gets odd...

A peek at the rifling showed it was a micro-groove barrel. Never seen a Mdl. 25 with a factory heavy barrel. A bit of MEK to remove the Krylon OD green and we discover that the rifle has a sleeve thats approx the same dia as the receiver in place over the barrel and filled with some sort of epoxy like acraglas or something. The muzzle had a flat crown, and with the spray paint looked like a nicely done target barrel.

Has anyone seen anything like this before? I wish I had pics (will try and get back with the guy and snap some) but its VERY well done and we didn't spot it until my husband saw the different color of the epoxy at the muzzle. Is there any real plus or minus to this? Or is it just purely cosmetic? Wrapped barrels are one thing and I understand the weight savings, but this is another thing entirely.

 

[DMann]

Re: Odd 22lr barrel mod.

There was an article in Precision Shooting a couple of years or so ago about sleeving like this. It certainly seemed like a logical way to get a stiffer barrel, but the article did this on a 7mm Rem Mag and one would think the insulating quality of the epoxy filler would accelerate barrel wear.

On a 22LR, not a problem.

Let us know how it turns out.

 

[gunnergirl81]

Re: Odd 22lr barrel mod.

Its certainly gotten my husband intrigued. He was planning on bedding our Marlin 25 into an old 40X stock to use as his trainer. But when he mocked it up it looked funny with the light barrel so he bought a heavy blank to rebarrel it. His chief complaint though was that he'd lose the micro-groove barrel.

Maybe we'll do a before and after test and see if this improves or degrades the rifles performance. But I still think its mainly a cosmetic thing on a 22.

Any old school rimfire boys with insight on this? The guy said he got it from his dad this way.

 

[DMann]

Re: Odd 22lr barrel mod.

Were it me, I would do the sleeve in aluminum and use an end cap on the muzzle so the barrel is stretched or tensioned between the ends. That way you are tuning out vibration but not adding heat.

I have also wondered about wrapping a barrel with aluminum wire. One would think you could get the stiffness and the heat dissipation similar to the Lothar Walther aluminum sleeved barrels, but without having to precisely machine a barrel and sleeve.

 

[gunnergirl81]

Re: Odd 22lr barrel mod.

Thats a great idea! It puts more of a performance element into it than just a cosmestic one. We had a 10/22 barrel that used a tension system with a carbon sleeve. Weighed like nothing. Why didn't we think of that?

I think what really got my husbands mind going is wondering whats under that sleeve. Was the barrel reprofiled? Is it solid resin the full length? We may never know. But if nothing else its inspired us to look at unique alternatives.

 

[DMann]

Re: Odd 22lr barrel mod.

Sorry - I zoned out looking at your avatar.

I'd bet a dollar to a doughnut it is the factory barrel - possibly with sights - encased in epoxy.

Have fun with it and keep us posted.

 

[toolmaker]

Re: Odd 22lr barrel mod.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kenda</div><div class="ubbcode-body">A friend of a co-worker wanted to get his Marlin 22 bolt gun's barrel shortened and the muzzle threaded. So he brought the rifle over for us to take a look. Its a model 25, like one we have, but it has a heavy barrel.

Now, here's where it gets odd...

A peek at the rifling showed it was a micro-groove barrel. Never seen a Mdl. 25 with a factory heavy barrel. A bit of MEK to remove the Krylon OD green and we discover that the rifle has a sleeve thats approx the same dia as the receiver in place over the barrel and filled with some sort of epoxy like acraglas or something. The muzzle had a flat crown, and with the spray paint looked like a nicely done target barrel.

Has anyone seen anything like this before? I wish I had pics (will try and get back with the guy and snap some) but its VERY well done and we didn't spot it until my husband saw the different color of the epoxy at the muzzle. Is there any real plus or minus to this? Or is it just purely cosmetic? Wrapped barrels are one thing and I understand the weight savings, but this is another thing entirely. </div></div> There is a company in S.C. that does this modification, they call it the ''straight jacket barrel system''. www.teludynetech.com

 

[Hellbender]

Re: Odd 22lr barrel mod.

You can also buy .22 barrel liners from Brownells.

 

[gunnergirl81]

Re: Odd 22lr barrel mod.

toolmaker-
My husband actually remembers seeing a news story on the TTI guys. Don't know how the dissapate heat with all that.

We're all now thinking in this case the mod was cosmetic in nature, and on anything other than a 22 would have been detrimental to performance and longevity.

But it did get us thinking and may have inspired some experimenting. As it sits the Marlin-Glenfield 25 looks puny and akward sitting in the 40X stock. But Jim is strongly against doing things to look cool that have no functional purpose. Hence the heavy barrel blank to make a new target barrel. Now, with the idea of using a sleeve and threaded cap to tension the tube and stiffen the tapered barrel, we can retain the micro-groove barrel. At the very least we can shoot some baseline sessions with the rifle in stock trim and compare it to when we have it done to see if there is any noticeable increase in performance. Worse case, we scrap the sleeved barrel and replace it with a new tube.

Now all we have to do is find the time...