I was sorting through an accumulation of .38 ACP this morning, and found a Remington (REM-UMC 38 ACP) blank. It has a slightly tapered mouth with a cannelure just below the mouth to hold a red card wad in place. I question that blanks such as this would function through an automatic pistol, requiring that they be manually inserted and ejected. Could this possibly have a military purpose other than for use in a pistol?
Guy - I have seventeen different .38 ACP blanks in my collection. Some have a factory look to them, some do not. I doubt that any are military. There were some tool guns in this caliber. I have a couple of stud-driver rounds as well. Some of them may be tool blanks, although I don’t know that. Some also are likely cinema blanks. If you look closely at a lot of the “.45s” in various movies, they are actually Spanish Stars and often obviously of a caliber of about 9mm. Some probably are 9mm Para, while others are likely 9mm Largo, most of which either will use the semi-rimmed .38 round, or can easy be altered to use it by very slight work on the breech face and extractor. Something, I think, about being easier to make into functioning semiautomatic blank firing guns. Doc Av would know more about this than I do, though.
At any rate, it is a caliber where blanks are often found.