If it was me personally, I'd go for the .50 or even a .45. I have 2 .50s right now but I hunt with them. You don't need the stopping power of a huge ball to kill paper, and I doubt you'll be shooting that far to begin with to have to contend with the wind. The smaller caliber will be easier on your shoulder and wallet as both the ball & the powder charge is smaller as you go down in caliber.
Sometimes you earthlings REALLY amaze me!