Eley Limited is a British manufacturer of firearms cartridges. Historically the company has produced a broad variety of ammunition, but today specialises in .22 Long Rifle cartridges for competitive target shooting. At the 2020 Tokyo Olympics, six of the twelve medals for cartridge rifle and pistol were won using Eley ammunition.

The .303 British or 7.7×56mmR, is a .303-inch (7.7 mm) calibre rimmed tapered rifle cartridge. The .303 inch bore diameter is measured between rifling lands as is the common practice in Europe which follows the traditional black powder convention.