For the average person there is little or no difference between the 45 ot 50 cal. The main reason they talk about more range for the 45 is lighter bullets. The 45 shoots a 41 cal bullet of 145 to 195 grains with upto 150 gr of powder. The 50 cal uses 44 0r 45 cal bullets from 160 to 350 grains with 150 gr of powder. You can obtain about the same speeds from a 50 with light bullets. I like the Knight 200 grain red hot bullets with 110 to 120 gr of pyrodex. I think the 50 will give you much more flexability for different animals with different bullets and charges. Another thing to think about is some states require at least 50 cal for elk, bears, moose, or other game. Either cal will handle deer at proper ranges but the smaller 45 cal bullets lack a little on larger stuff. My Knight 50 cal has dropped 2 black bears in their tracks with heavy lead bullets, and killed lots of deer with lighter sabots.