Thread: Barrel threading

https://bulletin.accurateshooter.com...ter-is-better/

Interesting thoughts.

Jeez, a 3/4 die nut slides straight over most NZ barrel profiles! Some can't be threaded any bigger than 1/2 UNC or 1/2 UNF in .308 calibers...

While it is a possible issue for most of the slim profile barrels we have in NZ if the barrel was going to bell out I would expect it would have done it at the time it was profiled to the sporter contours we commonly use. If it's a heavy truck axle target type barrel yeah I can definitely see this being an issue if you wanted to put a 1/2" thread on the end and it was a .308 sized barrel.

The usual common practice is to go to the biggest thread size you can on the barrel to leave the most meat on it, for a lot of them it's 14x1 or 9/16 but some are barely able to fit 1/2" on there. 5/8 threads are getting up there in my experience, not routinely encountered until you get up to things like the .338 calibers.

Some of the new Rugers, the standard Hawkeye for one, and the Ranch in 7.62x39, bell out at the end of the barrel to fit a 5/8x24 thread. I suppose it’s good having a meaty thread, but certificate looks weird on the end of the barrel. Would also stop you having a properly fitted rear bushing, as the thread is a lot wider to get over than the barrel is where it would be resting

Of all the variables effecting accuracy, I would think finding blame in a slightly wider exit...not much more than 10mm at the tip of the barrel as grasping at straws.

Originally Posted by trapperjohn

Of all the variables effecting accuracy, I would think finding blame in a slightly wider exit...not much more than 10mm at the tip of the barrel as grasping at straws.

Not too far fetched - slugging and cutting your barrel at a 'tight' spot is fairly well known. Probably not going to affect normal hunting accuracy though.

On the other hand when you over torquing your muzzle device, it will fix the bore diameter opening up problem

See video from Brownells https://www.youtube.com/watch?v=m8BAOMcSJGQ

This has been my solution to the problem. Simply cut your threads around twice as long as normal and make a bush that threads on. Install with red loctite and recut the shoulder face to be sure its square with the bore.

If you keep it reasonably slim, the barrel dia will often be larger than the shoulder where the suppressor bush is.

My 1/2" 1:20 thread cap will slide about 1/4" onto end of mates savage 7mm magnum unthreaded barrel.

Originally Posted by Micky Duck

My 1/2" 1:20 thread cap will slide about 1/4" onto end of mates savage 7mm magnum unthreaded barrel.

That is a mighty skinny barrel. Probably around 2mm wall thickness at the muzzle.

True that...I was shocked.

Originally Posted by SixtyTen

This has been my solution to the problem. Simply cut your threads around twice as long as normal and make a bush that threads on. Install with red loctite and recut the shoulder face to be sure its square with the bore.

If you keep it reasonably slim, the barrel dia will often be larger than the shoulder where the suppressor bush is.

Attachment 259664

From the 'looks weird, but is effective' file! Nice work.

I like barrels that have enough meat to do a 14x1 thread at least . But it does not always happen how I want. I once fitted a brake with 1/2-28 thread on a 300 win mag savage that the customers said was not shooting properly. I tested the gun with factory precision hunter ammo and was getting under 1/2moa 3 shot groups at 100m.

Originally Posted by SixtyTen

This has been my solution to the problem. Simply cut your threads around twice as long as normal and make a bush that threads on. Install with red loctite and recut the shoulder face to be sure its square with the bore.

If you keep it reasonably slim, the barrel dia will often be larger than the shoulder where the suppressor bush is.

Attachment 259664

Yep I have done that a few times

I have kept a 14x1 thread on 223, 243 (share a hardy stealth) and even my 358 but thats getting marginal, not much meat under the threads. however i was wanting to keep barrel weight down so the truflight guys went as thin as they were comfortable with on the barrel conture.
Z

14x1 is what I go for when getting any of mine done except for 22lr, 1/2 x 20 is fine for that