Tippmann X7
by Bill Mills - Photos by Dawn Mills - Nov 2007

Features HowItWorks Disassembly Adjustment Testing Data

The X7 relies on the same basic valve system as the Tippmann Model 98 and A5, a blowback semi-auto system with an inline bolt.

The X7's valve lies in the center of the system, behind it is the hammer. At rest, the valve is supplied by gas pressure fed from the bottom-line ASA through the tombstone fitting and into the valve, and the mainspring is compressed behind the valve.

The only thing keeping the hammer from flying forward is the sear, a see-saw like lever that latches into a notch in the bottom of the hammer. When the trigger is pulled it presses upwards on the front of the sear, tilting the back of the sear down, allowing the hammer to fly forward, driven by the mainspring.

A link rod connects the hammer to the bolt, so that as the hammer moves forward, the bolt also moves, pushing a paintball from the breech into the back of the barrel. As the bolt reaches the front of its stroke, sealing off the breech, the hammer strikes the valve.

The impact of the hammer on the valve presses the cup-seal inward, away from it's seat, opening a path for gas to flow through chambers milled in the side of the valve body, through the power tube and bolt, propelling the paintball out of the barrel.

A small amount of gas is also able to escape from the back of the valve, which serves to blow the hammer back – hence the name blowback semi-auto. A side tap allows some of this blowback gas to expand into the Cyclone feed piston.

Just how much gas is released, depends on how hard the hammer strikes the valve, as this has an affect on both how long (valve dwell) and how far (valve flow rate) the valve opens. Many paintgun designs use adjustment of mainspring compression to adjust the marker's velocity. The drawback to this, is that changes in mainspring pressure affect the marker's ability to re-cock and cycle properly. With the X7, velocity control is achieved instead with a flow limiter.

In front of the valve body, inside of the power tube, an adjuster screw interferes with the flow of gas from the valve into the bolt. This screw is accessible from the outside of the marker. Turning it anti-clockwise moves it further into the path of the gas, restricting its flow, and lowering velocity. Backing the screw out has the opposite effect.

Continue to Disassembly .