I believe the best bet is to use an honest deer caliber with bullets on the light end. Before anyone lambastes me hear me out. Deer are easy to kill, period. What other big game animal can be killed just as easily with a .223 or a 45/70. For a high bang/flop percentage I believe that a caliber between .270 and .30 would be best. In less you have the ability to shoot over 400 yards, the magnum calibers aren't needed. Even if you can consistently hit a deer at 1,000 yards, the bullets that are loaded in magnums are built to stay in one piece at magnum velocities. That is the reason that guys will feel disapointed when their new .270wsm doesn't kill as fast as their old .270.

My opinion, so it must be true:

Calibers smaller than .270 need bullets that are at the top end of the weight range, and bullets that are heavy for caliber don't expand as easily as lighter bullets. They work great, just don't expand as quickly as a lighter bullet would.

Most calibers over .30 are also built for critters larger than deer. If a .338 was loaded with a bullet that expanded violently on a deer, then it would probably cripple an elk. Exceptions of course are true deer calibers like the .35 Remington, but it's not a bang/flop round.

If you want the highest probability of a DRT kill with a lung shot, then look at either a .270 with a 130 grain or a 30-06/.308 with a 150 grain bullet. And don't worry about premium bullets, a plain old core-lokt will work best.