Sportclay - that worked fine. Those are the same as my box. I thought mine came empty, but it had one round with it. I found a note in my old collection catalog indicating a round in my collection came from that box. I probably should just leave rounds like that in the box, but I have always kind of kept my box collection as a separate entity to my cartridge collection, because for me,
the boxes are actually part of my library because of the information they often carry on the labels. Admittedly, I collect any auto pistol box, even if the information on it is useless to me, or even some boxes which are absolutely plain.
About that pressure test Type 14 Japanese pistol. I have seen one in the MacCleary Nambu collection years and years ago. Mac is long departed from us and I don’t even know for sure what happened to his collection, although I have my hunches. I can’t tell you much about it because I never really researched it. My article was more concerned with guns that the average guy might run into, and I felt the pressure-test guns were pretty much beyond that class. I am not even sure of what the cartridge they used looked like - that is, was it like a lot of copper-crush rounds with an alignment slot cut in the head and a largem usually covered hole in the case the diameter of the copper pellet to be crushed.
The wonderful book on Japanese handguns, “Japanese Hand Cannons,” and the volume that updated it, have some information on it. If you wish, I could scan the appropriate pages and send them to you by email. I don’t recall how much there is, but I am sure I saw a picture of one of the guns in the book.