I keep reading through the 3 pages(so far) of great responses to the original question. It really helps me gather my own thoughts on the next rifle I want to own. I have 2 50's. Love'em both. That said, back when I FIRST got into shooting muzzleloaders in the late 1970's if I knew then what I know now..I'd have a .54 for hunting and most likely a .40 for punching paper. I went with 50's all these years.
So, here I am, wanting to spec. a new small caliber rifle for punching paper ONLY.
I read all the great reviews and experiences with the .40, but I'm not sure there's enough difference from my 50's to justify a new rifle. This is especially true when I read of folks loading 60-70 gns of 3f in their 40's. Heck, that's what I'm shooting in my 50.
As someone here pointed out, the real differences most people notice when comparing small caliber rifles are more to do with design than caliber. This new rifle will be a flintlock. I want a long barrel, purely for esthetics. I'm thinking 40"-42". I'm still trying to read as much as I can regarding the question of barrel diameter vs. length vs. straight vs. swamped. That's my biggest hanging point right now. It will be either a .36 or a .40 when all is said and done. I don't hunt much anymore so all the "hunting advantages" of one caliber over another are lost in this decision. IF I get a chance to hunt deer or hogs, I'll be taking one of my .50's. Back to design then: I'm a simple Southern guy. "Golden Age" Dickert-type rifles are a bit "Showy" for me. One of the Southern Mountain style rifles is just fine.
There it is....just writing all this down for the first time in this forum helps sort the variety of choices. Thanks for listening to my rambling.
Comments welcome.