Well, the question is....of what advantage would it be, and I can't really think of any.
The accuracy range of the ball is greater than the effective range of the buck shot...and the buck shot it's self really has no accuracy...so really all it's going to do is make peripheral hits and damage meat. And if you missed with the ball, and hit with a couple or three buck-shots, most likely all you'll get is a wounded deer. Would be just blind luck, an accident if one of them little balls hit the heart. But i'm thinking that you are not going to miss with the ball, until the deer is WAY out of effective buck-shot range.
I've tried buck-shot many years ago, and found that it's effective range is way LESS than a roundball, anyway you look at it. Round ball from a smoothbore has a good 50 yard range, both in terms of accuracy and terminal ballistics. Personally I would not use a FULL load of buck shot much over 25 yards. With buck-n-ball, you are thowing what...three tiny buck-shot balls? If a full load of buckshot is inferior to a single ball, which it is, what advantage can there be to adding three or four?
Buck and ball goes back to the military theory that it's good to wound the enemy too, because then the wounded man requires care and attention from his comrads. For hunting there's not any advantage to wounding the game. I'm not sure buck-n-ball has ever been taken seriously as a hunting load.
All things considered I'd say put a single large calibre round ball in the heart lung area and forget about adding three .30 calibre balls in the butt, gut, back-straps, or the air.
Rat