For years I made brass powder measures, but nothing as fancy as these. I always made the top of the measure larger than the bore of the intended caliber. So, one could tip the full measure into the barrel, and simply drop it, jarring any powder that was in the tube out. The loop on the top of mine was made from a big brass cotter key. I originally started making them for shotguns, and trade muskets, because I had come into a substantial amount of brass tubing in the proper size. But, got into other sizes as shooters requested them.
Very nice work.
Hungry Horse