The Biwarip machine carbine is a prototype British submachine gun.
The Biwarip was designed in the late 1930s, and submitted to the British Small Arms Committee for testing in August 1938. It was a very handy weapon, and a modern one at that. However, it was too light to sustain any sort of accurate fire, and was rejected with no recommendations for improvement.
The Biwarip was a fairy simple weapon; it had no sights, stock, perforated handguard and a side-mounted magazine well. It fited using blowback. Four years after the Biwarip was tested, George William Patchett presented his submachine gun design to the Ordnance Board in 1942, which was very similar to the Biwarip.