Olin Winchester

Winchester is the ammunition arm of Olin Corporation, a chemicals company listed on the New York Stock Exchange, and it reports as one of Olin's three business segments alongside chlor alkali products and epoxy. The brand is far older than that structure. Winchester has been loading cartridges since the nineteenth century, and Olin has owned the name since 1931. Headquarters sit in East Alton, Illinois, next to the plant that has been the company's home since before the First World War, with centrefire pistol and rifle production largely shifted to a facility opened in Oxford, Mississippi in 2011. A further plant in Manitowoc, Wisconsin came in April 2025 with the purchase of small calibre manufacturing assets and brass shellcase capability from AMMO, Inc.

The commercial half of the segment is what most people see. Winchester loads shotshells, rimfire cartridges and centrefire rifle and pistol ammunition for hunters and recreational shooters, and it sells a separate line of duty and training ammunition to police agencies. An industrial products business supplies powder-actuated loads for construction tools, which is a small line with steady demand. Winchester Australia, based at Geelong, gives the segment a manufacturing footprint outside the United States.

Military work is the part that matters most to defence buyers, and the arrangement is unusual. Since 1 October 2020 Winchester has held the contract to manage and operate the Lake City Army Ammunition Plant at Independence, Missouri. Lake City is government owned and contractor operated, meaning the Army owns the plant and Winchester runs it, producing 5.56mm, 7.62mm and .50 calibre ammunition along with cartridge cases and components for the services. The initial term ran seven years and the Army has extended it by three more. The contract also permits commercial production at the site, which is why Lake City brass turns up in civilian ammunition. Winchester describes itself as the largest supplier of small calibre ammunition to the US military.

Lake City is also where the Army is building capacity for its new rifle cartridge. Ground was broken in February 2025 on a facility to produce 6.8mm ammunition for the Next Generation Squad Weapon, work managed through Army Contracting Command at Rock Island with Winchester involved in the construction and production programme. Labour relations at the plant have not been smooth. About 1,350 workers represented by IAM Local 778 ratified a contract to end a strike that had halted work at the Missouri operation. The segment's ammunition reaches infantry rifles, mounted weapons, police duty holsters and hunting camps from broadly the same production base. Olin reports Winchester separately from its chlor alkali and epoxy businesses, so the segment's sales and margins are visible to anyone reading the annual filing, which is unusual disclosure for an ammunition maker of this size.