Unscrew the pressure tube end cap. Put a drop of Crossman Pell Gun Oil on the nipple end of each cart. Drop one cart. in nipple forward, toward the trigger, drop the other on top, nipple out, towards the muzzle. Screw the pressure tube cap on as far as it will go, snug. Back the cap off till you feel the CO2 presure lock the cap, about 1/8 to 1/4 turn. Cock the bolt, snap off a "dry" shot to pierce the receiver end cart. Let the CO2 temp. warm a bit and go shootin.'