It is the 25-20ss not the Winchester round. Trying to scrounge up some brass and used dies. I will load black powder only and see what happens.
Shortgrub
I believe really early 1885 Winchesters marked .25-20 Win are the .25-20 version. And the .25-20 with the more pronounced shoulder (now called the .25-20 Win) came later.
Dies are costly, but you don't really need them for much. If you can avoid needing to FL size the first time, then all you need to do is some sort of crimp and you can seat/crimp a .25-20 SS in a .25-20 Win die (which are mucho cheaper.
