In The Olden Days a lot of National Guard units didn't have really decent ranges upon which to shoot high power rifles with FMJ bullets. The solution was to issue these gallery loads for them to practice with at short range. It was also popular among Army and National Guard units to shoot indoors with their service rifles, hence the term Gallery Practice ammunition. This was at a time before they saw fit to issue .22's, which later became standard practice. I don't know what the heck they do now - have classes on political correctness instead? (Joking, but it wouldn't surprise me.)
Along with loaded ammo for this practice they also issued these tools so the guys could reload their own gallery ammo. Probably had the newbies do all the grunt work while the old guys had the fun of shooting!
