4.38×30mm Libra

The 4.38×30mm Libra (.17 Libra) is a centerfire cartridge designed for use in personal defense weapons. It was designed and has been manufactured by ČZW for use in their ČZW-438.

The cartridge is based on a .22 Hornet cartridge converted to a rimless design and necked down to .17 calibre. The .17 Libra has been standardized by C.I.P. to a pressure of 4300 bar.