Gunsmithing barrel threading question

[wfjames22]

I had a rifle (.260REM) built and the smith threaded the barrel for an AAC 51T brake (5/8x24) that I supplied and made a matching thread protector for it. When I got the rifle back, I put the brake on and it fit perfectly. I shifted gears with my suppressor plans and sold the brake. I just purchased a TBAC 30P-1 (5/8x24) and today I went to shoot with my dealer to try out my suppressor.

Well, the suppressor would not thread onto the 260's barrel. I also have a factory threaded Remington 5R and the suppressor went right on it. The thread protector from my smith built 260 will thread on my factory threaded 5R perfectly, but the thread protector from the 5R will not thread onto the 260. The thread protector, just like the suppressor, will only go onto my 260 barrel about 2.5 revolutions.

My question is, would it be a dumbass idea to take a 5/8x24 die and run it over the threads on my 260 barrel? I dont really feel like it could hurt at this point, because I am going to have the barrel chopped/rethreaded anyway if it doesnt work.

 

[wnroscoe]

Re: barrel threading question

The smith probably used your brake/QD mount as the gauge, thats not a good idea. That being said, I have a client that did just that one day to a barrel I had threaded. Yes, my gauge fit the threads, they were a class 3 fit. I think he wanted a class 2 fit and is why he did it. It worked fine as should your's as the die nut did/should follow whats already there. Just go slow and dont force it and keep cutting oil/fluid on it. It probably wont cut much off as is as the brakes/QD mounts are pretyy close the way they come.

 

[turbo54]

Re: barrel threading question

Depending on the size of the thread relief at the base of your muzzle tgreads, the die may not get to ALL of them...

Definitely sounds like the smith didn't bother threading according to the thread wires.

 

[LRI]

Re: barrel threading question

Maybe try a tap inside the can first? If its coated/plated it may have a little fungus in the root of the thread. If it does nothing, all you've done is bought yourself a useful tool for later in life. You won't hurt anything.

C.

 

[lw8]

Re: barrel threading question

Check the can for carbon buildup in the threads....common problem.

 

[wfjames22]

Re: barrel threading question

Thanks for the responses. I doubt I will be doing anything to the can, that seems pretty ignorant considering it's the most expensive/hard to get part of this equation. Anyway, it seems like the problem is in the threads on the 260 muzzle, not a single thread protector, flash hider, suppressor, etc that we had out there yesterday would fit on my gun.

Plus the can fit on multiple rifles that were out there. If I believed that there was a problem with the can, I would be sending it back to TBAC, not trying to fix it myself.

About the carbon build up, the can had never had a round fired through it when I tried to put it on the 260 the first time.

With my inexperience with suppressors and muzzle threads, I figured that my can should go on any muzzle with 5/8x24 threads. Obviously thats not the case, or the threads on the 260 are not right.

 

[wnroscoe]

Re: barrel threading question

If the can, QD mount and thread cap fits multiple rifles, the problem is in your muzzle threads, not the can.

Cutting Oil
Die Nut
Extreme care
No Rush

The only other solution is to pick the threads back up in the lathe. This isnt hard but, the person doing it better know exactly what they're doing. There's an even shorter list of those that I'd trust for this.

 

[STR]

Re: barrel threading question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">If the can, QD mount and thread cap fits multiple rifles, the problem is in your muzzle threads, not the can.

Cutting Oil
Die Nut
Extreme care
No Rush

The only other solution is to pick the threads back up in the lathe. This isnt hard but, the person doing it better know exactly what they're doing. There's an even shorter list of those that I'd trust for this. </div></div>

Run the die, which is cheap to do. You will not hurt a thing if you do it as William said. Best of luck.

 

[wfjames22]

Re: barrel threading question

Mr Roscoe...when you say dont force it, how much force is too much? I know that this will be hard to quantify, but any help would be appreciated. I received a die today from MSC and I am attempting to run it on my muzzle threads now.

 

[wnroscoe]

Re: barrel threading question

There will be some resistance as I suspect your die is for a class 2 fit. You will see metal being cut off. Just turn it slow, not fast. I should have mentioned earlier to see if a class 3 die nut was available. The die will follow the muzzle threads if started straight. Oil it up and go.

If you jack it up just box it up and send it to me since the die nut was my idea. I'll thread it 5/8x24 class 3 and check it with a certified ring gauge at N/C, you just pay return shipping.

 

[wfjames22]

Re: barrel threading question

Wow, I appreciate that offer but if I end up sending it to you, I will pay for any work you do to it. You definitely dont owe me any work. The die idea was my own, you just answered my questions about the process. I dont think that the die is going to work, at least with me running it.

When is a good time to call you tomorrow and pick your brain for a second, sir?

Thanks,
Frank

 

[wnroscoe]

Re: barrel threading question

Anytime.

 

[i_rep]

Re: barrel threading question

I had that very thing happen with a new can and new rifle.

I ended up buying the tap and die and just chasing the threads on the rifle and the NEW can. Problem solved and costs me about 30 bucks in tools that may be used again if needed.

My can would work on other rifles and same for thread caps and brakes but for some reason that new can would not work on that new rifle from a very well known smith here (the rifle also had a brake on it and a thread protector). Things would all interchange except the can on that one rifle.

 

[turbo54]

Re: barrel threading question

Wnroscoe - over the course of a couple years, and multiple forums, I've seen nothing other than you being a top notch, first class person and outfit.

You can bet your ass I'll be sending work your way when I need it.

 

[bptactical]

Re: barrel threading question

If you just spin a standard die down it you stand a good chance of cutting the threads undersize. If your going to use a die use an adjustable die opened up and slowly adjust it until you get the fit you want.
Best bet is to pick them up on a lathe.

 

[wnroscoe]

Re: barrel threading question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Wnroscoe - over the course of a couple years, and multiple forums, I've seen nothing other than you being a top notch, first class person and outfit.

You can bet your ass I'll be sending work your way when I need it. </div></div>

Thanks but I'm just paying it forward. I've been in that barrel before and didnt like it

 

[Keith Johns]

Re: barrel threading question

Like BPTactical said an adjustable die is what to use. Just tighten it till the can fits. And don't hit the shoulder if you can avoid it because the shoulder is what is keeping the can straight.


Looks like Mr. Roscoe is taking care of you so you're good to go.



Damned if I didn't suggest this very thing to a guy several months back and caught flack for it. Ohh well