Well, I'll hit right in the middle between the suggestions of Don M and 30378. I switched from .30-06 to .243 as my deer gun two years ago. At the suggestion of several hunters on this board, I tried the Sierra 85 HPBT. It's done the job beautifully at ranges from 25 yards to about 150. The powder? IMR4350.
Regardless of caliber, shot placement is critical, and there's not doubt it becomes a bit more critical in the smaller calibers. If you're the kind of guy who has trouble passing up a bad shot, then I'd advise a heavier, tougher bullet, something like a Partition. But if you're a careful, ethical hunter, the 85 will work really well for you.