Bag of 50 factory new Winchester 307 Winchester unprimed brass cartridge cases, packaged from bulk.
The 307 Winchester cartridge was introduced by Winchester in 1982 to meet the demand of .300 Savage performance in a lever-action rifle equipped with a tubular magazine. It is nearly identical to the more common .308 Winchester cartridge, the only differences being a rimmed base and thicker case walls
Case mouths MAY not be perfectly round from the manufacturing process, this can be corrected by running brass through the size die (always recommended) prior to loading. Residue from the annealing process may leave a stain on the case neck that can be removed by tumbling. Annealing involves rapid heating then cooling to impart the shell cases with the proper hardness to securely hold bullets in place and provides flexibility to expand and contract through multiple firings.