smoky
A 357 Maximum would be my choice. It has a flat trajectory and ample power for deer. I have one in a Contender, I know it's not a factory chambering in the Encore. A 44 Mag would be my second choice, especially in the old 10" barrel style.
In my opinion the 480's and 454's are more than what is needed for deer, if elk or bear are on the menu then I'd consider them. (For those of you who like these calibers for deer, that's fine with me, I'm not knocking your choice, I just don't think they are needed for deer)
At 75 yds you don't need a "rifle" caliber, but they do normally group better than a traditional pistol round at 100 yds. I had a 260 Remington 15" barrel that I foolishly parted with, wish I had it back.