As in the words of Clint Eastwood/Dirty Harry, "A mans' gotta know his limitations." Figure out the maximum distance you can keep all six shots on a paper plate, shoot while standing, not using a rest.
I must say, I will NEVER, EVER shoot off hand at much range with a handgun at deer, no matter the handgun. I've made shots at 60 yards with a .357 magnum, one at 90 with my .30-30 Contender, used a rest to do it. I've passed on off hand shots beyond 25 yards. "ALWAYS use a rest, boy!" Them's my grandpa's words echoing back to me from 1963 when I shot my first with a .257 Roberts. If I should always use a rest with a rifle, why should I then shoot off hand with a handgun? Now, I've made shots off hand RUNNING at 50 yards, that' I've done with a rifle several times. But, with a handgun, I will ALWAYS heed my grandpa's instructions. I can't make those running 50 yard shots off hand with a handgun. 25 yards static is about the limit. You don't get no points for style shooting off hand, nobody there, but you and the game. I want a clean kill with a well placed shot, myself.
SO, I practice for handgun hunting like I shoot in the field, off my shooting stick, cross stix, blind rest, whatever, but rested. I shoot a lot off hand, for fun, but in the field I have some kind of a rest, always. Most I've ever done on game off hand with a pistol is leaning back against a tree shooting off my knees at 50 yard squirrel with an accurate .22 pistol. Now, if you consider shooting from a rest "cheatin'", well then, I happily cheat.