W231
W231 is a smokeless powder manufactured by the Hodgdon Powder Company and marketed under the Winchester trade name. Hodgdon licensed the Winchester brand in January 2006, assuming all manufacturing and support responsibilities.[1] Prior to this Winchester brand powders were manufactured by the Olin Corporation.
W231 is commonly used in metallic cartridge reloading and handloading. It is used primarily for pistol cartridges. While the product label states "ball" powder, W231 is a flake-type powder; although it is finer in grain than other flake powders such as Bullseye. The misnomer has been a subject of conjecture; some stating the powder starts as a ball, and is flattened in the manufacturing process, and others, that the powder was intended for use in military, or ball type ammunition.