This rotary magazine bolt-action rifle is chambered for the exciting.17 caliber Hornady Magnum Rimfire cartridge. The.17 HMR is a high-velocity performer that is the answer to a varmint hunter's prayers. The.17 HMR propels a 17-grain,.17 caliber high-performance jacketed synthetic-tip bullet at over 2,550 feet per second, more than 25% faster than a.22 Magnum. This ultimately means a flatter trajectory and superior accuracy for the target range and for small game hunting alike. All Ruger 77/17 rifles incorporate Ruger's patented nine round detachable rotary magazine and Ruger's patented scope mounting system with integral scope bases and medium-height rings.