Thanks for all the interesting ideas. It would really be nice to pin down what these were made from. Both came from the same collection so it could have been an individual making them for his own use.
The two loads weigh 221gr and 217gr respectively with the polished round being the lightest. In a normal 9mmP case this would imply a 155gr bullet. The diameter of the case just above the end of the taper ahead of the groove is 9.47mm and 9.55mm with the polished round being the smaller diameter. The case diameter of a 38 Special is 9,55mm at this same point. The CM diameter on the two 9mm just below the bevel to the bullet is 9.75mm on both while a 38Spl is 9.51mm at this point. Both cases swell a bit toward the CM indicating that the bullet swelled the case a bit when it was seated. The rim thickness is very different on the two rounds as you can see from the photo. The polished round has a thickness of 1.47mm and the other 1.22mm. The rim thickness on a 38Spl is about 1.5mm.
Does anyone else have one of these cartridges?
Dennis, I have a whole selection of the post-WWII 9x19mm made from 38 Special cases. Many were made by the Wagner Gun Room in Ohio which must have had a big operation since I have a full box of their rounds and have seen other boxes. These rounds all seem to have lead bullets, either RN or Truncated.