Thread: Where to measure barrel length?

Originally Posted by Magnetite

Bolt face to muzzle.

This is correct.
It is quite a bit shorter than the barrel looks. For instance, the OAL of a .308 cartridge is 2.800" (therabouts) so a 20" barrel will only have about 17" of rifling and bullet travel. For instance, the thread attaching the barrel to the receiver is part of the barrel length. It can be hard to locate the bolt face as its usually some way back inside the receiver (except in the SMLE or break action rifles).
Have a look on some barrel makers web sites eg Welcome to Shilen Rifles, Inc.