Norma .300 Winchester Short Magnum 170 Grain Rapid Expansion Polymer Tip Brass Cased Rifle Ammo 20 Rounds. 300 Winchester Short Magnum is a 7.62mm short action magnum cartridge with considerable effect. It is very similiar to the regular .300 Winchester Magnum in terms of ballistics but takes advantage of the short action design which allows more powder to sit closer to the flash hole. When the primer ignites it allows a more uniform burn which in turn translates into more efficient use of energy. A 300 WSM can therefore achieve the same ballistics with less powder. Specifications for Norma .300 Winchester Short Magnum 170 Grain Rapid Expansion Polymer Tip (REPT) Brass Cased Rifle Ammunition: Manufacturer: Norma Caliber: .300 Winchester Short Magnum Number of Rounds: 20 Bullet Type: Rapid Expansion Polymer Tip (REPT) Bullet Weight: 170 grain Cartridge Case Material: Brass Application: Hunting Package Type: Box Primer Style: Centerfire Lead Free: No Package Contents: Norma .300 Winchester Short Magnum 170 Grain Rapid Expansion Polymer Tip (REPT) Brass Cased Rifle Ammunition What is Norma .300 Winchester Short Magnum 170 Grain Rapid Expansion Polymer Tip (REPT) Brass Cased Rifle Ammunition good for? The manufacturer suggests that it is suitable for hunting.