AK, what is better: 14x1LH, or 1/2x28?

[Kano383]

I'll have to thread an AK muzzle. I know that the "original" AK muzzle thread is 14x1LH, but with the thin barrel there is nothing left for a shoulder... So I was thinking of going with 1/2x28, which would at the same time open a much wider variety of ready-made devices.

What do the AK-nuts think? And no, staying original is not on my list of concerns...

 

[briansmithwins]

On a normal AK the FSB acts as the shoulder. Are you doing something very different?

BSW

 

[David Hoback]

If you are running 7.62, 1/2x28 is a bit thin walled. If it’s 5.45 or 5.56, sure...go 1/2”

 

[Kano383]

7.62, FSB removed.

1/2x28 is on the thin side, yes. The only alternative more stable than 14 and thicker than 1/2" would be 13.5x1L, but that makes it harder to find items to mount without adaptor...

 

[DerMerchant]

Are you planning on using a variety of muzzle devices or just one?

 

[Telekinesis]

This kind of depends on the purpose of threading (brake, flash hider, suppressor?) and how much you would want to be able to change muzzle devices. For a 7.62 AK I would try to get to something more in line with 5/8 x 24, even if you have to build a permanently attached thread adapter (think Tornado Tech) in order to build up a real shoulder to a diameter larger than your barrel OD. The only trick is maintaining concentricity so that you don’t have tolerance stacking issues.

For rifles, 1/2 x 28 is the standard thread pitch used on 5.56 weapons, so there could be a risk of accidentally mounting a 5.56 muzzle device (or suppressor!) and shoving a 7.62 bullet through a 5.56 hole. If you’re planning on putting one flash hider on and leaving it, maybe it doesn’t matter as much, but I’d recommend using a thread pitch that doesn’t lend itself to making a mistake like that.

 

[Kano383]

Are you planning on using a variety of muzzle devices or just one?

Flash hider or linear comp, and suppressor.

This kind of depends on the purpose of threading (brake, flash hider, suppressor?) and how much you would want to be able to change muzzle devices. For a 7.62 AK I would try to get to something more in line with 5/8 x 24, even if you have to build a permanently attached thread adapter (think Tornado Tech) in order to build up a real shoulder to a diameter larger than your barrel OD. The only trick is maintaining concentricity so that you don’t have tolerance stacking issues.

For rifles, 1/2 x 28 is the standard thread pitch used on 5.56 weapons, so there could be a risk of accidentally mounting a 5.56 muzzle device (or suppressor!) and shoving a 7.62 bullet through a 5.56 hole. If you’re planning on putting one flash hider on and leaving it, maybe it doesn’t matter as much, but I’d recommend using a thread pitch that doesn’t lend itself to making a mistake like that.

The permanent adapter could be an idea, turning the barrel first and maybe adding a journal behind it to ensure concentricity.

I've seen that Rifle Dynamics is using 1/2x28 on their 7.62 builds, though.

 

[Deus Machina]

What kind of tooling do you have?
If you have access to a lathe, I'd personally go with the more common 14x1 and alter the muzzle device instead of the barrel, if possible.

 

[748]

I had an M1 carbine barrel turned for 1/2-28, seems like it will work.
I dot have a silencer for it yet, it's definitely going to be a form 1 build.

 

[Kano383]

What kind of tooling do you have?
If you have access to a lathe, I'd personally go with the more common 14x1 and alter the muzzle device instead of the barrel, if possible.

I have access to a lathe, but the muzzle is not threaded, so it's a blank page...