We, as more savvy hunters know, that the whitetail deer has significant morphological differences across its range, and is found in widely varying terrain. Different choices will be needed in different scenarios
"New and Improved" has been a selling mantra for about two centuries. It's the opinion of the seller trying to make the sale in many cases, from what I've seen.
YET a 225 grain, .530 diameter, patched round ball has been harvesting whitetails, mule deer, elk, and moose for hundreds of years, with very humane results. Still works quite well today (personal experience).
Out to 150 yards, no worries.
IF you really want something that looks modern..., you can always up the lead by a mere 75 grains ....,
Lee 300 grain REAL bullet
I intend to try the below bullet out of a .450 bushmaster cartridge this year in a single shot rifle. My county now allows straight walled cartridges for deer in "regular gun" deer season when in the past it was only shotgun or muzzle loader. I opted decades ago for muzzle loader because shotguns back then were slugs in a smoothbore "slug barrel", and I wanted better accuracy past 50 yards.
Yes the Eastern whitetail in Maryland is about 40% smaller than those up in PA. Still I think this slug going at 1500 fps from the .450 bushmaster in a hand-loaded cartridge will work fine out to 100 yards, and I hunt in heavy brush. I bet it would work on whitetails anywhere (IF I got close enough I admit). It's smaller diameter than my round ball, but it's 25 grains heavier, and the hollow point may help it expand, BUT if it doesn't..., it's still a big hole.
250 grain .452 PHP (Pentagon Hollow Point)
Now you folks using smaller diameter, lighter, longer bullets pushing above 1600 fps are going to need a gas check or a copper jacket to keep the leading down, even when a hard lead alloy is available. But as long as the bullet that you folks are using is going to give you some expansion but stay intact after impact...,
I think you do better much better to concern yourself with how accurate you and your rifle are with your cartridge, than what the cartridge is going to do for you with terminal ballistics.
LD