50-60 Peabody Rimfire question

Here are a coulpe of 50-60 Peabody rimfires.


Number 1 has a case length of 1.4980", a total length of 1.8515" and a total weight of 560 Grains.
Number 2 has a case length of 1.4830", a total length of 1.9005" and a weight of only 537 grains.

The total weight difference of 23 grains I assume is due to bullet weight.

The first one I think was manufactured by C.D. Leet or UMC. Any thoughts as to who manufactures #2?

I’ve found references of 50-60 Peabody rimfires being manufactured by C.D. Leet, UMC, Springfield Armory (and/or Frankford Arsenal) as well as Winchester. The UMC cartridges were probably manufactured on equipment obtained from C.D. Leet. Are there any others?

Hoyem’s “The History and Development of Small Arms Ammunition Vol 1” list the bullet weight for the 50-60 Peabody as 400 grains with 60 grains of powder. Barber in “The Rimfire Cartridge” list a bullet weight of 320 to 402 grains and a powder charge of 60 grains. Barber also list the total weight of the cartridge as 556 to 576 grains. This total weight range seems unrealistic if a 320 grain bullet was used.

Datig “Cartridge for Collectors Vol 4” suggest Winchester did manufactured a “.56-60-320" Peabody beginning in 1877. A reported Winchester 50-60 is pictured in Barber’s book.
Can anyone confirm Winchester made a 50-60 Peabody rimfire with a 320 grain bullet? Also were any ever manufactured with bullets other than 400 or 320 grains?

Paul