In terms of say..an 870 barrel, does it start at the chamber, or is the extra side part that locks it into the receiver counted? And for handgun barrels, feed ramp included as the entire piece of metal is the barrel?
Jay, "the distance from the muzzle of the barrel to and including the chamber".
Extra side parts and feed ramps aren't part of the chamber, I'd think. I believe we're measuring the inside of the barrel, not the outside. Much easier than trying to account for all the little projecting metal pieces holding the barrel into place.