The .220 Rook / 5.7x18mmR, also known as the .220 Long Centrefire, is an obsolete British centerfire rifle cartridge.
It was designed and produced in Britain in the 1880s.
It is believed to be an early centrefire version of the .22 Long Rifle rimfire cartridge.
[2][3] The .220 Rook fired a bullet of 30 grains (1.9 g) weight driven by 5 grains (0.32 g) of black powder, it was designed for hunting small game and target shooting, although many considered it too small for practical hunting purposes.
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