Alexander Arms is an American manufacturer of firearms. It is most known for the .50 Beowulf cartridge designed by its founder, Bill Alexander. The company produces AR-15s chambered in .50 Beowulf and 6.5mm Grendel, which it designed in cooperation with Competition Shooting Sports. Alexander Arms also produces both upper receivers and complete rifles, chambered in .17 HMR, for the AR-15 platform. The company also produces ammunition and accessories for its products.