Chiral!@kaia@brotka.st Hmm. From a VERY quick internet search and knowing nothing of firearms and the related stuff: My guess: British 37mm number 4 signal pistol, circa 1945 if the image is anything to go by. Similar things are termed "Model M" or "Number 4", and I have no idea if there's a difference or what that difference might be. One site selling similar things mentions "For aircraft", but how it would be used, I dunno.
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