Is a barrel extension legal?

[Bigfoot]

I've posted here before about using long barrels instead of suppressors for pistol caliber subsonic shooting. Since then I put a 28" sporter profile barrel on my 10/22 and it's almost silent with Rem Subsonics. I can shoot it indoors without hearing protection. Now I'm looking at this .40S&W Mech-Tech carbine. I could have someone build a long barrel but it would need some expensive machining because of the mounting system. I'm wondering if I could thread the 16" barrel instead and attach an 10-12" extension on it, probably with no rifling to match up.

I don't remember seeing anything like this. Possibly because pistol caliber carbines aren't common and rifle calibers could cause problems with their much higher pressures.

I wonder about the legality because anything that reduces the sound could be deemed a suppressor.

I live in a very liberal area or I'd just get a suppressor.

Bigfoot

[HUNTER2]

They still sell a barrel extension for shotguns called a METRO. About 26" long and screws in where the choke tube goes. Use it with some special shells made by federal. Really reduces sound signature. The guy that come up with it to hunt crows with. I have even seen it used on geese. Never thought about it until I read your post. No answer, but good question......

[snipecatcher]

It is my understanding that if the purpose of the extension is to reduce the sound, then it is a sound suppressor and subject to NFA rules. Some others may chime in, but that's the way I interpret it. I have a 28" barrel .22 also, and it is as quiet as my 300 whisper suppressed.
-Dan

[amafrank]

I think Dan's got it on the regs....
You might do some searching on bloop tubes. They were fairly popular at one time for helping to control the muzzle blast that upset the bullet. All they were was a long tube bored over the bullet diameter by some amount to allow the gas to escape in a controlled manner rather than creating turbulence and disturbing the bullet. I don't know how well they worked but its worth looking into.


Frank

[sha-ul]

I can't say where I read it, but I remember seeing that barrel extensions were legal, so long as they didn't reduce the sound level more than 2db

on company had to do a massive recall after the ATF measured the reduced the sound too much& declared the whole lot to be suppressors.

[Bigfoot]

Not looking good.

Ok, what if it's welded or blind pinned on?