Gunsmithing Muzzle threading question
- Thread starter Paul_R
- Start date
It would depend on the muzzle device you would like to use. In general (and IMHO) thread to the largest thread pitch (assuming proper shoulder height) possible for the device(s) you intend to use. My friend has gotten his last couple of barrels threaded 3/4-24 for this TBAC brakes even though they are 6.5mm and 6mm bores. The more meat left on the barrel the better (for the most part).
TBAC makes brakes that are 3/4-24 threaded. However, with my silencers, I would need to go down to 5/8-24 because that's what my brakes are threaded for and have no other options.
TBAC makes brakes that are 3/4-24 threaded. However, with my silencers, I would need to go down to 5/8-24 because that's what my brakes are threaded for and have no other options.
5/8-24 is a common thread pattern for .338 barrels. AI uses M18x1.5 for .338 and DTA use 3/4-24 (from what I have read).
Larger would probably be better (again, in my opinion), but you are limited by the brake you would like to use.
Here is an article about not taking too much metal off the muzzle...
http://bulletin.accurateshooter.com/2015/04/muzzle-threading-dont-remove-too-much-steel/
http://bulletin.accurateshooter.com/2015/04/muzzle-threading-dont-remove-too-much-steel/
Interesting stuff. Given that bore uniformity is a proven variable for consistency/accuracy, this really gets my attention.
I don't understand why he didn't take this to it's logical next step, which would be to quantify the difference -what size pin would extend past the narrowing?
It would be interesting to do some testing on this related to how the threads are cut, and whether or not this is a variable that could mitigate, or exacerbate the bore swelling. Is this an issue caused by heat if DOC is aggressive, and feed rate is fast? Is it caused by tool pressure? If done slowly, with light passes (as on a manual), is the result different?
Knowing the issue is one thing, but knowing the cause(s)- and whether or not there's a method of threadcutting that is more effective at reducing or eliminating this would help in those situations where there's no choice but to use a smaller thread than would be ideal.
I don't understand why he didn't take this to it's logical next step, which would be to quantify the difference -what size pin would extend past the narrowing?
It would be interesting to do some testing on this related to how the threads are cut, and whether or not this is a variable that could mitigate, or exacerbate the bore swelling. Is this an issue caused by heat if DOC is aggressive, and feed rate is fast? Is it caused by tool pressure? If done slowly, with light passes (as on a manual), is the result different?
Knowing the issue is one thing, but knowing the cause(s)- and whether or not there's a method of threadcutting that is more effective at reducing or eliminating this would help in those situations where there's no choice but to use a smaller thread than would be ideal.
