Size for thread protector
- Thread starter nof60
- Start date
There will be an answer from a gunsmith type but you can probably remove the brake, measure the thread (possibly 1/2-28, unless it's metric - the ones on my suppressors when I lived in NZ were 1/2-20 which is why I'm unsure), and wrap the threads in electrical tape until the thread protector arrives? (Local hardware should be able to sell you a thread gauge or if you take the brake to a machine shop they'll be able to measure it for you) Or is there a gun store near you? "under the northern lights" is a pretty big area
- Location
- Western Manitoba
Not even close to being a gunsmith, but typically need to come up with accurate Outside Diameter (OD) of the threads, and then the thread pitch - so could be in Imperial - as mentioned - like 1/2" x 28 threads per inch, or it could be metric - like 12 mm, and then that uses the metric designations - like M12 - 1.25 or whatever (OD in mm and distance in mm between each thread "peak") To get real fussy, also includes the thread form - is it 60 degree or 55 degree or something else - is it pointy tips to the threads and grooves or rounded? - the thread "form" probably only an issue if you are trying to machine one to fit... Gotta love trying to figure out a match to somebody's previous "custom" work. Not to mention that is assuming that a normal "right hand thread" was installed, but someone may have felt that a left hand thread was a "better idea".
If you are positive you will never want the brake on, I suggest either cutting the threads off and recrowning the barrel or use the brake itself to make the thread protector. If you think there is a chance (however slight) you will want the brake on again, you need to remove it and measure what you need. Unfortunately even that is no guarantee. I’ve seen more than a few shop made brakes that were made with sloppy threads, the barrel threaded fairly tight to them that would not accept a properly sized thread protector or other brake.
Best idea is to take it or mail to a smith to sort out.
But I can pretty much guarantee you it’s not 1/2-28 on a 375
Best idea is to take it or mail to a smith to sort out.
But I can pretty much guarantee you it’s not 1/2-28 on a 375
- Location
- Nova Scotia
What is the Diameter of the threaded section?
5/8-24 is normally common on 30 cal and higher, but Ive also seen 14x1mm LH & RH
5/8-24 is normally common on 30 cal and higher, but Ive also seen 14x1mm LH & RH
Unless the machine shop has a federal license to work on firearms they can not touch it...
Take it to a gunsmith or at the least take it off and measure the thread...and go from there. My guess is it is 9/16 x 24
I made a cap for a fellow matching the contour of his brake and made it exactly the same weight as requested.
Take it to a gunsmith or at the least take it off and measure the thread...and go from there. My guess is it is 9/16 x 24
I made a cap for a fellow matching the contour of his brake and made it exactly the same weight as requested.
Last edited:
do you have a caliper and tape measure? should be able to figure it out.
You can take the brake to a shop without the gun , would be fine.
If you don't want it, you could go all babba and just cut the front end off ahead of the barrel and you have your thread protector. chances are it will look like hell.
You can take the brake to a shop without the gun , would be fine.
If you don't want it, you could go all babba and just cut the front end off ahead of the barrel and you have your thread protector. chances are it will look like hell.
Unless the machine shop has a federal license to work on firearms they can not touch it...
Take it to a gunsmith or at the least take it off and measure the thread...and go from there. My guess is it is 9/16 x 24
I made a cap for a fellow matching the contour of his brake and made it exactly the same weight as requested.
Yep I was going to take it off. They can measure the threads and fab a protector or cut the brake. Nearest smith is probably 1400 km
- Location
- Nova Scotia
Its easier than you think. Measure the threads with a tape measure. Then find a bolt with the same thread pitch and lay it over. If you don't got a TPI gauge.
Cocked&Locked
CGN Ultra frequent flyer
- Location
- S. Ontario
A dial or digital caliper, yes. Find what the OD measures for a starting point. That will give you a good indication if it is inch or metric.
Then you need inch and metric thread pitch gauges to confirm exactly what it is.
Only problem with that is the machine shop would have to have a bolt on hand exactly that thread size to confirm what it is, very unlikely to have it. I will guess that 9/16-24 is what you have, as guntech said.
Best to take the complete gun to the machine shop so they can measure the external threads quickly and easily as I described above, while you wait. Takes only a couple of minutes for any remotely competent machinist.
Last edited:
