User Manual
HM17021 / HM17021S Mounting Instructions
Install the adjustable base in the dovetail of the rifle with the pivot end toward the muzzle.
If the receiver has a step down to the barrel, anchor the anti-walk pin over the front of the
receiver. If the receiver and barrel are intrical, loosen the anti-walk pin retaining screw located
in the front of the base and remove the anti-walk pin.
Tighten the four side clamp screws enough to secure the base during the sight in process.
Assemble the rings and scope on the base ensuring proper eye relief.
Without adjusting the scope turrets, shoot the air rifle at a target 20 yards away.
Measure the amount that the pellet is low from the aiming point.
Slightly loosen the side clamp screws enough so the center section of the base can pivot.
Loosen the elevation adjustment lock screw in the back of the base.
Turn the elevation adjustment screw clockwise to move the pellet impact up. One full clockwise
revolution will move the pellet impact up 7” at 20 yards.
Retighten the four side clamp screws enough to secure the base again.
Shoot the air rifle and measure the pellet impact.
Once the impact is within 1” finish tightening the side clamp screws to 30 inch pounds.
Tighten the elevation adjustment lock screw to 13 inch pounds.
Finish sighting in your air rifle using the scope turrets.