A friend is the proud new owner of a RRA. He said that it has an "air gauged barrel" which is much better than the Bushmaster barrels.

What is an air gauged barrel?

Thanks,
G-36

Someone has to know.......

Air gauging is a process for measuring the bore. It uses air pressure against a ball or float to determine how 'true' the barrel is to spec. It is very accurite and is used mostly on match quality barrels to guarantee accuracy.

I was told by Bushmaster that their barrels are air gauged.

Quoted: I was told by Bushmaster that their barrels are air gauged.

I was told the same, too.

It is an inspection process not a manufacturing process.  By itself it does nothing.

As stated, air gaging is a process for measuring the diameter of the bore along the length of the bore.  By itself, it does nothing and guarantees nothing.  It does not affect the quality of the bore being inspected.  

The key is to use the measurements to select a barrel with absolutely uniform diameter all along its length; or to select a barrel which gets tighter from the throat to the muzzle.   It can be used to deselect barrels which get larger from the throat to the muzzle or have a wide spot in their middle,...

It can also be used by the manufacturer to gage the efficacy of process variations to guide them in selecting a process which produces more uniform barrel more of the time.

Quoted: It is an inspection process not a manufacturing process.  By itself it does nothing. As stated, air gaging is a process for measuring the diameter of the bore along the length of the bore.  By itself, it does nothing and guarantees nothing.  It does not affect the quality of the bore being inspected.   It can also be used by the manufacturer to gage the efficacy of process variations to guide them in selecting a process which produces more uniform barrel more of the time.

Can you tell us how the air-guage process actually works? I have wondered about this myself.

IIRC, the ball is passed down through the bore while air is pushed through at a calibrated volume.  If the barrel get's wider or narrow air passes around the ball at a change in velocity/pressure.  It's kind of old tech and doesn't mean as much these days but always sounds good.