Minimum barrel thickness for a M14x1 thread?

[CCH]

Gents,

 

What is the minimum diameter muzzle you would have threaded M14x1?

A have obtained a barrel for a sporter in 30.06 and it seems that the muzzle end will finish out at 0.600" or 15.25mm.

 

ASE ultra seem to reccomend a minimum of 15.5mm for that thread and I am wondering how significant 0.25mm will be to the end result?

 

Just looking for a vox pop of opinions really, I want to avoid a 1/2" thread if at all possible but may be forced to go with it if M14 is a bad idea.

 

With thanks,

 

 

[ejg223]

1/4x28 or 1/4" UNEF might be an alternative.

edi

[eldon]

1/4x28 or 1/4" UNEF might be an alternative.

edi

 

Really Edi........ LOL..... the bullet is bigger than the thread, hows that work?

 

Seriously, I think he meant 1/2" x 20 tpi or 28 tpi

[ejg223]

Really Edi........ LOL..... the bullet is bigger than the thread, hows that work?

 

Seriously, I think he meant 1/2" x 20 tpi or 28 tpi

off course, meant 1/2"

edi

[sonic]

if I remember right metric threaded mods have a spigot to line them up 1/2" 20 has a shoulder so the .25 may mean wobbly mod.

If the bore is not perfectly down the centre of the barrel you may have less still. I can see no gain from 1/2" 28 over 1/2" 20 the latter is more common here

have a look at this http://jacksonrifles.com/zz-silencers/files/t8-t4-manual.pdf page 3 explains

[Danpd]

I usually like at least 1mm of shoulder per side on a 14x1NS so 16mm would be the minimum I would go.

 

1/2" threads on 30.cal barrels is not something I advocate, as firstly the thread relief with a max class 2a fit is at .439 leaving only approx .066 per side of barrel between the bore and the moderator. And secondly this creates a loose spot right at the muzzle which does nothing for accuracy.

 

I would look at going 14x1 spigot, which will allow the largest thread possible for your barrel, whilst still maintaining integrity at the muzzle.

[ejg223]

if I remember right metric threaded mods have a spigot to line them up 1/2" 20 has a shoulder so the .25 may mean wobbly mod.

If the bore is not perfectly down the centre of the barrel you may have less still. I can see no gain from 1/2" 28 over 1/2" 20 the latter is more common here

have a look at this http://jacksonrifles.com/zz-silencers/files/t8-t4-manual.pdf page 3 explains

 

Big enough difference, between 20 and 28 pitch. Calculate percentage when using a 30 cal, stiffness? bending strength? every tenth of a mm counts.

28 pitch is a way better thread for the purpose compared to 20 anyway.

edi

[sonic]

I was thinking more on the lines of more mods in 20 but. yes less thread depth in 28 should be stronger.

 

could you afford to lose a bit of the end of the barrel you'd gain a bit of width how much would depend on the profile. you'd need to check.

[CCH]

Thank you for the replies.

 

The plan B was to go with a 1/2"x28 UNEF thread if the 14x1 was inadvisable but whilst I'm sure it would be fine, in a .30 cal does not leave much meat around the muzzle. It's not so much a matter of pressure, the wall thickness is more than adequate, but rather of robustness should it take a knock.

 

I like the idea of a M14 spigot, it could even be made a little oversize to fit the specific moderator even more closely. Am I correct in thinking that providing the very small shoulder remaining isn't dinged, the spigot will protect against the moderator being knocked out of alignment?

[sonic]

I believe that its the spigot rather than the shoulder that aligns the mod