You can increase your velocity by up to 25fps by simply replacing your stock bolt with this Liquid venturi bolt. This delrin bolt directs all of the air from the valve into your bolt instead of around it where air normally escapes the breech, causing your velocity to be lower than it should be.
 
*These are all original run production from the late 90's early 2000's. Supplies are LIMITED. Some items may have minor blemmishes from storage. The pricing reflects this.