US Cartridge, 37mm Blank
Typical blank ammunition of the old type is made up of 37mm Cartridge Case Mk. I, Mk. IA1 or Mk. IA2 with appropriate primer; a cylindrically shaped charge of black powder enclosed in a silk bag or moisture proof cellophane bag with a hole in the center for flitting over the primer; a cardboard wad for holding the black powder charge in place; and a paper closing cup sealed with Pettman cement.
The new type of blank ammunition for 37mm guns consists of the appropriate cartridge case adapted at either end for a central tube which is of a size to seat a 10 gauge blank shotgun shell. This 10 gauge blank shell (correct nomenclature is Cartridge, Blank, 10 Gauge) is fired when the firing pin of the weapon strikes its primer. The blank round for the M1916 Gun consists of the Adapter M1 (Mk. I, Mk. IA1 or Mk. IA2 Cartridge Case with tube for adaptation to 10 gauge shotgun shell) and 10 gauge blank cartridge.
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