Barrel measuring question

[AR15]

If you start with a large enough blank you could machine a monocore into the end then thread the od of that for a shroud to contain the blast.

[Attleborough]

My 2d worth.

To be a barrel, I thought it had to be pressure bearing?

If so, a muzzle break is not pressure bearing and will not be classed as part of the barrel whether permanantly fixed or not?

[AR15]

doesn't matter, whatever is permanently attached to the barrel is part of the overall length of said barrel.
You can weld on some scaffolding pole if you like to get it up to legal length. It has to be legal Sec1 length before chambering as until then its nothing but a blank.

[ovenpaa]

Once it is fixed in place it becomes part of the barrel and is part of the overall length. In theory you could take a 12" barrel, counter bore it for 8" and peeper pot the 8" length to give a theoretical 4" barrel with 8" muzzle brake. Not sure why anyone would consider such a thing though

EDIT - You beat me to it Paul :)

[AR15]

:)

[polemass]

Aha,I think I can see the light in the tunnel(or is it tracer...?),thanks,JB

[Ian]

How about adding a rod to extend the barrel length in the same way as is added to a butt to extend the overall length? Does it have to be a tube?

[breacher]

How about adding a rod to extend the barrel length in the same way as is added to a butt to extend the overall length? Does it have to be a tube?

How about a permanently attached bayonet ?

[safetyfirst]

Or a gun with a knife on it with a gun in the knife that fires knives.

Section 1 apparently.

[TattooedGun]

Or a gun with a knife on it with a gun in the knife that fires knives.

Section 1 apparently.

Only if the barrel that the gun that fires knives is over 12" or 24 if it's smoothbore....