This leads to some interesting phenomenon involving cartridge nomenclature and notation in the factory ledger.  

Here, coming up at RIA auction, we have a .50-100-450 documented to be the first .50-100-450 to be shipped.  There is some good research discussion in the auction narrative:

https://cdn.rockislandauction.com/flipbooks/87/BOOK1/index.html?utm_source=Rock+Island+Auction+News&utm_campaign=1d0c2ec4bc-2022_11_11_xxx&utm_medium=email&utm_term=0_1f4b8db853-1d0c2ec4bc-148909845#p=43

Here, we have a previously sold .50-100-450 documented to be the earliest known .50-100-450.  However, the difference is it is actually marked .50-100.  Interesting discussion in this auction narrative as well (we’ve discussed this rifle as well):

https://www.rockislandauction.com/detail/80/3007/earliest-known-winchester-model-1886-50100450-rifle

I have been fascinated by the .50 caliber Model 1886’s for the better fraction of my life.  I’ve brought the topic up before and always appreciated the input it received.