I wish that Bill’s card showed the total weight of the cartridges, and the headstamp. I know the headstamp on rounds like this is insignificant to the identification of the maker, but it does help in the identification of other specimens believed to be the same as “the known one.”
It is interesting that the Bellmore Johnson company loaded the ones shown, as while they do, or did, manufactured the Winchester-Licensed reproduction of the famous Winchester 10 Gauge cannon, I never thought of them as really a firearms-related company. I had my round identified as a commercial cartridge of some other make.
My cartridge is loaded in a new (never previously fired) W-W 45 AUTO case, and the total cartridge weight is 180.9 grains (11.52 grams). It has a three-segment plastic sabot that is semi-transparent, that is, more than just translucent. is 0.133" (3.38 mm) deep, and shows two copper segments with white nylon apparent between the two segments, and the bottom of the cavity being copper as well. That is what the Woodin X-rays seem to show.
Barring a different ID (with documentation) of the round I have described, I will reclassify it in my own collection. I certainly trust the Lab’s ID far, far above my own original ID.