Winchester Rifle Brass Winchester Unprimed 50 Cases/Bag. The 25-20 Winchester Unprimed Rifle Brass is manufactured with strict quality control to ensure the consistency that reloaders demand. With a variety of gauges and cavities to choose from the Winchester Unprimed Brass Cartridge Case keeps up with the rigors of today's modern small bore rifles. For the most part small bore rifles that utilize these casings achieve great ballistics with relatively simple loading. However with any small bore caliber they create a fair amount of recoil so it is important to maintain a light recoil. As part of this strict manufacturing regimen the cases slightly expand during firing to help with the force that creates recoil. As part of this the cases slightly expand during the firing process. Specifications for Winchester .25-20 Winchester Unprimed Rifle Brass: Manufacturer: Winchester Caliber: .25-20 Winchester Primed: No Brass Quantity: 50 Piece Cartridge Case Material: Brass Package Contents: Winchester .25-20 Winchester Unprimed Rifle Brass Winchester Rifle Brass .25-20 Winchester Unprimed 50 Cases/Bag WSC2520U