Quote:
Originally Posted by Blue Avenger
You measure the BARREL. The portion inside the receiver counts as part of the barrel length, as would any muzzle brake that is pinned or soldered to eliminate quick removal. Threaded tight is not permanent!
The Part of the receiver that holds the bolt and trigger dose not count as barrel length. It dose count as total length of the gun, as will the stock when installed.
Perhaps a bit more precisely, for a rifle, shotgun or closed breach handgun (single shots, semi-autos) the length of the barrel includes the chamber since it's measured from the closed breach face. For a revolver, the barrel length does not include the cylinder.
One simple way to check barrel length is to make up a dowel rod marked at the exact minimum length (16" for a rifle, 18' for a shotgun) and drop it down the barrel until it hits the closed bolt. If the mark is inside the muzzle, you are legal.