Gewichtslehre also translates (with Google) as “Weight Theory” but with Han’s input, here it seems more likely to be “Weight Gauge”.
Separately John Moss has supported this with examples from his collection of cartridges to calibrate cartridge loading machines to detect loads that are too heavy (in one example-with the bottom half of the case being blackened) or too light (with the tip of the case black). I have seen such a machine in operation at the Royal Thai Army Arsenal in 1969. Their basic load line, for 30-06, was from Lake City, but at the end was a German made device from the 1930s that rejected loaded rounds into a container if they were too light or too heavy. As I watched a round was rejected and the officer held it in his hand and announced there was no core in the bullet. Then he gave it to me. It current home is the Woodin Lab.
I am going to consider it a weight gauge cartridge. I weighted 20 normal aluminum case rounds and they ranged from 152.6gr - 154.1gr with an average of 153.6. the Maroon base round weigh 154.9gr so it could be the heavy weight gauge!
Again, thanks to all. There may be Forum, members who disagree or have added info. If so, please post. Dissenting opinions welcome!