MJS, thanks for reminding me about the .38-50 Rem--I'd simply forgotten what it was and was confusing it with the ancestor of the .38-55 Ballard, the .38-50 Ballard (an entirely different ctg.). I looked up the .38-50 Rem and found a letter from Ken Waters advising me that it was one of the best options for a project I was contemplating (finally made that rifle a .40-60 Maynard).
Interesting about the extra "soup" the .38-50 Rem provides you for BP Silueta. I know a guy in NYS who uses a Hepburn-actioned custom rifle in .38-55 "Win." for that game. Claims it works fine (everyone else finds it marginal--some use .38-56 Win instead for the same reason you use the .38-50 Rem--room for more horsepower!).
I'm in favor of resurrecting all the old rimmed BP rounds--even shoot black in my .22 Hornet sometimes, a la .22 WCF....my kid calls this load the "pop/stink"!