Kay machine carbine

The Kay machine carbine was an idea proposed by an artilleryman, Gunner Kay, in 1943. The concept was to build a new submachine gun using die-cast metals, specifically Mazak, a corrosion-resistant zinc alloy. There was much concern at the Armament Design Department over whether a zinc alloy would be of adequate strength, which the Chief Superintendent doubted. It was suggested that the Kay could still be built, although preferably from another metal. Unfortunately, among all the debate over the materials used in the fabrication of the Kay machine carbine, there was seemingly little actual consideration given to the design itself; although the safety mechanism, trigger mechanism, and chamber were all noted to be of interest, no written description was ever provided. Ultimately the project was not given the go-ahead, as it was perceived to offer no advantage over the existing Sten.