45 Acp Bore Sighter Cartridge Red Laser Sight Boresighter S&W Bullet Pistol 1911 Top quality item is designed for fast, efficient and most accurate gun zeroing. Caliper: 45 ACP, please see out other listings for different sizes. Range: 1-100 yards. Laser Type: Class IIIA Visible Red Laser. Wavelength: 635nm - 650nm.