Mossie,
You don't say what kind of carbine you are referring to. If it's a breechloader, I cannot say. But if it's a muzzleloader, I can tell you from experience, they do just fine. My brother shoots a .50 cal Traditions flinter with a 21" barrel and I've seen him make 3 clean kills on good size PA whitetails. He likes the carbine because he hunts from a climbing stand and the short barrel works better for him. He shoots the same load as I do, 90 grains GOEX 2f with a patched round ball and 4F in the pan. The only difference I noticed is a little more recoil and muzzle jump.
Finnwolf