I have killed a lot of deer with the 41 magnum but I don't remember ever using a factory load on one. The fast & light crowd really swears by the Sierra 170 gr bullet & some people have taken some big animals with that bullet. It has a good reputation.
I've taken somewhere between 35-40 deer with the 230 gr Keith cast bullet & it's done a great job. I cast all my bullets as soft as possible & still maintain accuracy. I don't think I've ever shot one twice.
I've also been using a 210 gr cast HP that is gas checked. I cast this bullet soft & it has a pretty big HP cavity. It's doing a great job of putting deer down fast!
I also have a 250 gr HP cast slug but haven't used it yet, this fall will be the first time for that bullet.

Dick