An ADL guard uses the front action screw which threads into the bottom of the receiver and a smaller screw in the rear that threads into the threads behind the magazine cut out. Another options is to bed a threaded pillar into the stock for the rear screw.
The smaller screw is the front guard screw or middle screw, the rear is a 1/4-28 screw and the front screw is 1/4-28 screw!
