The Peterson Cartridge Co. 10.36x77mm Brass is based on the .505 Gibbs, modified and necked down to 408 Caliber. The round was designed with a possible military need for a cartridge for anti-personnel, anti-sniper and anti-materiel roles with a (supersonic) precision range of 2,200 yards (2,000 m). Cartridge: 10.36x77mm Quantity: 50 The Peterson Cartridge Co. 10.36x77mm is annealed and final cleaned before leaving the factory. It comes packaged in a plastic ammo box to protect the cases during shipping and also for storage of loaded ammo. Mfg: Peterson Cartridge