Construction Guide:Cut out the three openings in the shieldAssemble the gun with the w/m base (having a slight angle at the front edge) sliding into the trunnion.Drop the barrel into the top of the trunnion and fix and then fix the sight bar where shown. Lastly drill out the wheel sockets with 0.8mm approx drill and fix the two wheels.Slide the assembled gun into the shield between the trunnion bottom flange and the two angled side supports.