The Action Army inner barrels with an inner diameter of 6.03 mm are precisely manufactured from brass. In order to prevent tarnishing / fogging on the inside and to keep friction as low as possible, all inner barrels are chrome-plated in a special process. This ensures perfect power output even at colder temperatures. The barrels are milled in a funnel shape at the front so that the drive air can escape better and the fired 6mm BB is not impaired in flight.

The strong outer diameter of 8.5 mm ensures particularly high stability and torsional rigidity. At the same time, this reduces the distance to the outer race, which means that the inner race has as little play as possible in the outer race.