Laser Bore Sight 20 Gauge Barrel Target Cartridge Boresighter for 20 GA shotgunsLaser Bore Sight 20 Gauge Barrel Target Cartridge Boresighter for 20 GA shotguns ITEM DESCRIPTION Laser Cartridge Boresighter for 20 Gauge Shotguns This compact boresighter system is designed for sighting in your rifles without firing a shot. Simply install the included batteries, place the entire assembly into the chamber, and gently close the action. The sight will emit a straight red laser beam, providing a precise reference for zeroing in your