I'm gonna toss my hat in the ring here, too.
Unless you really enjoy getting the sh*t kicked out of you, why not .50 cal.? With 1:48 twist as in T-C and many others, most rifles will give sufficient accuracy for informal competition and plinking without breaking the bank what with the current price of BP. For instance at rondy I shoot 50 gr. 3F under a .490" Patched round ball, the same load I've killed deer with.
For heavy game such as Elk, Moose, Griz, and Hogs, a Maxi or a Lee minie ball in it's several variations and weights or Lee's R.E.A.L.'s would do the job quite nicely.
We're not shooting Cape Buffalo or Elephant here.
Three Hawks