muzzle device on a barrel over 16

[Pentium9mm]

Does a muzzle device on a barrel over 16'', attached to pre -ban ( pre 1994 ) lower need to be pinned and welded ?
Sorry if this has been discuss before because i know i have seen it before but cant find it

 

[slap shot]

no

 

[MAJoe]

Where are you located? Mass? No it doesn’t.

 

[Pentium9mm]

Only came to work in Mass . I did update my real location .