What is the best way to measure barel length?
 

What is the best/proper way to measure the length of a rifle barrel that is already attached to the receiver?

Is the chamber length considered part of the barrel length for measuring?

Thanks in advance for any help provided.

Put the bolt in the forward position. But a cleaning rod in the barrel until it touches the bolt. Mark with a pen. Now measure the rod. The Feds will drop a pre cut rod into the barrel. If it does not stick out your barrel is too short.

Thank you!

Rick is exactly correct and that is the most accurate way of determining barrel length. many people will actually go an extra half to one inch over tp err on the side of it being legal.

That measurement is only what is non removable on the barrel. So if you have a compensator or flash hider and its not permanently attached as in welded or pinned it doesnt count on length.

Above is correct for rifles, shotguns and pistols, with the exception of revolvers.

Weapons should be cocked, so firing pin does not protrude, rod should be close to bore diameter, so you are not measuring an angled line thru the barrel.

With revolvers, open the cylinder, place a flat object across the forcing cone, THEN insert rod, mark, withdraw and measure.

Maybe I'm thinking of this wrong somehow but if it's a pre-measured rod at the minimum legal length, and it sticks out then the barrel must be too short right?

That's what Rick meant...