The measurement is from the face of the bolt to the end of the barrel. Google 5320.8 for the NFA Handbook published by the BATF.Overhill said:Than, the chamber (forcing cone) is included in min. barrel measurment? That leaves me with a problem if it is.
If i was to tap the barrel and install an extended choke tube, would it be legal. i have looked at all the data i could find and this (tube) is not mentioned, I would even be willing to solder the tube in as i would have no desire to change it. Any thoughts?
Unloaded, empty shotgun...
Bolt CLOSED...
With the barrel pointed straight up in the air, take a rod and drop it down the barrel, allow the rod to rest on top of the closed bolt.
If 18" or more of the rod protrudes from the barrel, your shot gun barrel is legal (as far as the Federal regulations are concerned).
If less than 18" of the rod protrudes from the barrel, (even by 1/32" your shot gun may be an NFA weapon or AOW.