Nope, not a .45. My brother went to a WW2 militia show in Mesa Az and because it was different, he bought a round, a single round, for a huge S&W N frame. He went to sell/trade some WW2 stuff and saw thiz thing. He didn't have a clue what it was for sure of what it was to be fired from. He didn't buy a gun, just a single round. For an N frame S&W. A Model 276. Or Model 210. 37MM tear gas. Ouch.