Gunsmithing Thread chaser for muzzle threads

[atombomb]

I have a barrel with a small ding right on the starting muzzle brake thread… I tried to start a muzzle brake on it to chase it or clean it up some, but there is not enough to get it started and me comfortably put any pressure on it… since I shoot suppressed, I need to clean it up and not affect the alignment of the can to the bore… Anyone have any thoughts or recommendations on a tool that would work? Or should I just file that one spot down?

 

[spife7980]

Custom barrel that the smith would refuse correcting because you filed on it? If so ask him.
If not and you have a file, that’s what I would do. Slowly. Carefully.

 

[iceng]

Thread file is what you seek. The have a bunch of thread pitches on the one file. Cheap and work well for quick repair of dings.

 

[atombomb]

Thread file is what you seek. The have a bunch of thread pitches on the one file. Cheap and work well for quick repair of dings.

Thanks, I had looked at those, but wasn’t sure if those pitches worked with the threading, isn’t it 2A or something special? But I’ll order one and give it a shot… gotta be better than a flat file...

 

[LeftyJason]

Thanks, I had looked at those, but wasn’t sure if those pitches worked with the threading, isn’t it 2A or something special? But I’ll order one and give it a shot… gotta be better than a flat file...

2a or 3a is the tolerance class of OD threads not profile shape. 2b or 3b is internal threads. UN shape is what you seek unless it is metric. 3's should always fit on a 2 or a 1, not necessarily the other way around.

To get different shapes (which you are not going to get into in guns) would go to something like a UNJF, UNJEF, or UNJS. The J stands for a different root radius, generally bigger. C is for course, F for fine, EF Is for extra fine. The S stands for a special size. Today at work we are grinding a 3.4980-24 UNJS-3a left hand thread. I also grind 1/2-28 UNJEF 3a and 9/16-18 UNJF-3A as well. All the threads I girng are in inconel. Aerospace turbine jet engine stuff.

 

[strikeeagle1]

You need to use a split die that can be applied beyond the faulty threads... I have a number of these for gunsmith use.
An example of what you need, just get the muzzle thread size.

 

[ma smith]

https://jawco.com/collections/thread-restoring-files/products/3-rethreading-file-set

 

[Huskydriver]

Thread file or a die as recommended above

 

[n2ishun]

Those thread files are for shit.....ask any mechanic that has had to use one twice, you'll find they didn't work either time.

The split die will work much better but since the *dink* in the threads is right at the tip of the barrel it might not do the job you want.

Swiss needle file is what you're looking for, with lots of patience and some care it will do what the others won't.