The Osprey Global 45 ACP Laser boresight will help you sight in your scope, red dot or laser without wasting ammunition. Just insert the Osprey Global 45 acp Laser boresight as you would your regular round. The Osprey Global 45 ACP Laser Boresight will project a red laser through the barrel. At thiry yards adjust your windage and elevation until the red laser and your crosshairs are lined up with the boresight laser. At a hundred yards you will now be on paper.