OPERATION: The 2004 BKO has a 2 way solenoid which blows the ram forward but relies on a spring to make it return. This is good in that it keeps the price low, but it's bad in that if your bolt is a bit too tight, the extra drag will slow your cycle times. When you air up your marker you won't see any immediate change in the BKO. Unlike the Bushmaster 2000 which cocks once you air it up, the BKO is cocked even without air due to the spring return. When you pull the trigger, the solenoid sends air into the ram chamber forcing it forward against spring tension to strike the valve. The bolt which is tied to the ram also moves forward, positions the ball and as the valve opens the air comes up through the gun, out the bolt and fires the ball.