US Army Alpha Black Tactical
by Bill Mills - Photos by Dawn Mills - March 2008

Features HowItWorks Disassembly Adjustment Testing Data

DISASSEMBLY - continued

A ring-shaped spring clip sits in a groove at the front of the valve body. This clip holds the front brass valve plug in place, keeping pressure on the valve spring, and is the tricky part of valve disassembly.

Taking the pressure of the spring and plug off of the spring clip is necessary for its removal. Simply pressing in on the front valve plug with a tool, will get it out of the way but leave the tool in the way. This is solved by sliding a hex-wrench into the valve's gas port, and releasing the plug, so that it presses against, and catches on the hex-wrench.

A few minutes of maneuvering with a sturdy pick can pry out the end of the spring clip, allowing the entire clip to then be worked out of its groove.

With the clip out, the valve plug can once again be depressed, and the hex-wrench removed. The pressure of the valve spring can be enough to push the plug out of the valve body at this point. Further pressure on the valve stem at the back of the valve with a small hex-wrench can be applied to push out the valve core and other components.

The rear valve face and o-ring may need to be fished out of the valve body with a pick.

Care should be taken with handling the brass valve face, as brass is a soft metal and it can be scratched with hard tools. The cup-seal, both sides of the brass valve face, and the rear valve o-ring must be clean and free of damage, as these are the surfaces that have to seal in order to prevent a “down the barrel” leak.

The valve is re-assembled in reverse order, making certain that the side of the brass valve face with the thin center wall goes in first, as this fits up against the front o-ring. Just as during disassembly, pressing in the front valve plug and keeping it compressed with a hex-wrench wedged through the gas inlet makes installation of the clip ring much easier.

After sliding the valve body into the rear of the power tube, the gas hose needs to be re-attached. To avoid leaks, a thread sealant must be used, either a putty such as that used from the factory, or PTFE pipe thread tape.

Before re-assembling the two halves of the Alpha Black's clamshell receiver, the support and guide pins for the trigger, sear and link rod must be checked to ensure that they are fully seated, as must the safety, and the two square nuts used to support the bottom-line.

The ball detent must be in place. The feedneck latch pin, and spring must be properly placed and aligned, which can be a bit tricky.

With all of the internals in place, the two receiver halves simply press together and are secured with their screws. The receiver screws are in two lengths, and looking at the marker end-on makes it easy to tell if a short screw or a long screw is needed for each hole. The barrel shroud must be in place before the lower front screw is reinstalled.

With the receiver back together, the bottom-line must be re-attached to the grip frame. The barrel, feedneck and stock can be re-attached, and the marker is ready for action.

Continue to Adjustment.