According to the UMC and REM-UMC catalog images (Thank you!) I see that, in addition to the standard 40 gr. B.P. cartridge there was an optional 28 gr. cartridge first listed in UMC 1906 and last listed in the 1915-1916 REM-UMC Catalogs.
If anyone would have a pic of the box with the 28gr call out, I would really appreciate it. Or if anyone would have a pic of a .44-40 b.p. box from that time period, I would really appreciate a pic of that.
Here is the UMC 1910 catalog cut…
Thank you very much for your help.