I have taken deer with a pistol. I did quite a bit of experimenting before I settled on two to use. The 54 caliber single shot I set up on a contender frame and loaded with a 54caliber PRB was very good deer gun. It was a bit heavy for a pistol though. The other I used was a black powder Ruger with 38 gr of P and a 457 ball with bore butter on top the cylinder after I loaded it. There are a lot of possible choices, I came to the conclusion that if you don't have a good tracking dog available the a large caliber single shot is best.