I thought I'd pass along this interesting video. It covers the, arguably, first fielded submachine gun: the Italian M1915 Villar Perosa made by OVP. It was originally designed for aircraft use, but later was used in ground warfare. One fun fact the host of the video didn't mention is the British actually tested it out chambered in their .455 Webley Automatic cartridge instead of the Italian 9mm Glisenti. It, evidently, didn't go anywhere because specimens in that caliber are very rare. Anywho, as I found the close up shots and info interesting, I thought I'd pass it along. Cheers.