30 Remington Rimmed?

I recently acquired a 1899 Hartley and Graham catalog and it has amongst the U.M.C. offered cartridges for sale, a cartridge pictured and labeled “30 Remington” It is rimmed, the engraving shows no head stamp other than a “U” marked primer. Is this a .30 Gov’t? or something entirely different? It appears to have a RN full metal patched bullet. Never heard of it. It would be presumptuous to assume that the pictured cartridges are to scale. If they are to scale this case is larger than the 30 Gov’t. ???

This “.30 Remington” was a short lived cartridge designed in 1895 for Remington-Lee magazine rifles, Remington Model 1896 single shot rifles, and Colt machine guns. It was also known as the “.30-220 Remington” or the “7.62 m/m Remington” and there are two rim diameter variations: one for rifles and another modified to work properly in both rifles and machine guns. Typical specimens of the “large rim” variation are not headstamped (primer marked U) and the “large rim” variation exist without a headstamp (primer marked U) and also with U.M.C. .30 R. headstamp. It was last listed in the UMC 1904 catalog.

The large rim unheadstamped variation is the one identified in Datig’s volume 1 p. 135 as the “8.1 m/m Lee-Nagant, M/92” (titled “.30 Remington-Lee-Nagant”).

How close is this round to the 7.62x54R Russian dimensionally?

The “large rim” variation is almost identical except for having a slightly smaller rim and head diameter (rim: 14.14-14.22 mm/.556-.559" & head: 12.19-12.22 mm/.479-.481").

Thanks for the info! Now I have another cartridge to add to the search.
Thanks again