In determining a bbl length, is the "official" measure

(A) from the bolt face to end of the bbl?

or

(B) are you supposed to figure out where the chamber ends and then figure the length of the bbl from that point to the end of the bbl.?

Trying to determine if a bbl is really a 16" or 14.5" or something else altogether

Like a first down in football, I guess it all depends on the where you measure from?

Thanks (in advance) for the Clarification!

"Bigger_Hammer"

1. Close the bolt on an empty chamber.
2. Put a wooden dowel down the barrel from the muzzle until it is in contact with the bolt face.
3. Mark end of barrel on dowel.
4. Remove dowel and measure barrel length.

HTH

Quoted: 1. Close the bolt on an empty chamber.

1a.  Make sure the hammer is cocked so the dowel will rest on the bolt face, not on the firing pin.

2. Put a wooden dowel down the barrel from the muzzle until it is in contact with the bolt face. 3. Mark end of barrel on dowel. 4. Remove dowel and measure barrel length. HTH