Valve for compressed gas gun

A compressed gas gun comprising:

• a gun body;
• a trigger;
• an upper chamber housing a bolt, the bolt moveable from a loading position to a firing position, the bolt having an aperture therethrough;
• a lower chamber comprising a valve assembly comprising:
• a high pressure chamber;
• a valve portion intermediate the high pressure chamber and a hammer portion of the lower chamber, the hammer portion of the lower chamber including a hammer moveable from a loading position adjacent a rear portion of the gun body to a firing position adjacent the valve portion of the lower chamber;
• a valve assembly provided in the valve portion of the lower chamber, the valve assembly comprising:
• a valve body defining an interior space having a first end with a channel therethrough and an opposite second end with an opening therethrough, and a valve aperture intermediate the first end and the second end;
• a valve spool having a portion disposed within the housing, and forming a gas balance chamber within the interior space adjacent the first end of the valve body, the valve spool having a stem extending through the channel in the valve body,
• the valve spool having a second end opposite the first end positioned adjacent the outer side of the second end of the valve body, the second end of the valve spool sized to close the opening in the second end of the valve body, and,
• a channel running through the valve spool and providing communication with the second end of the valve spool and the gas balance chamber;
• wherein the second end of the spool valve has an effective surface area greater than the effective surface area of the gas balance chamber;
• and,
• a trigger for initiating a firing operation of the compressed gas gun, wherein actuating the trigger causes the hammer to strike the stem of the valve spool.