This AR-pattern rifle is chambered for .25-45 Sharps cartridge, a proprietary round based on a .223 case necked up to .257. The "45" refers to length of the .223 case in millimeters. (Factory ammo with a Speer 87-grain bullet and Federal cases with the correct head stamp is available from Sharps Rifle Co.). Rifle uses AR-15 magazines and available in several configurations. Price shown is for base model. Introduced in 2015.