I use the .50 caliber Hornady 300gr XTP Sabot with (2) 50gr Hodgdon pellets in my muzzleloader or 300gr Hornady SST 12ga shotgun slugs in my H&R Ultra Slug Hunter. Sometime i use my T/C Contender(pistol) in .44 mag but i do not have any special or favorite loads.
I'm in Illinois and like alot of flat states we are only allowed shotgun, muzzleloader or pistol during firearms season. Sure would like to use a rifle but my muzzy is the closest thing to that for me.
The 30-06 is my favorite. I like a Remington 180 grain PSP Core Lokt. I like heavy for caliber bullets because many of my shots have been quartering shots in cover, not a classic broadside shot in the open.
In Kentucky, 100 yards is a long shot. For heavy cover, I like the .35 Remington with a Remington 200 grain SP Core Lokt. The .35 Remington is considered by some to be a "brush buster". This means a condition in which most shots will be at close range, not where the bullet will travel through brush and push the brush out of the way.
At 25 yards, the .35 Remington is already 35 caliber and the heavy soft nose bullet at 2000 fps will mushroom and transfer a lot of energy into thin skinned game. My experience is that a short range shot with a .35 Remington really knocks deer down and, properly hit, they rarely travel more than a few yards.
Seriously, 243 Winchester or 6mm Remington will take a whitetail down at ranges out to 800+ yards if you can read the wind and dope your rifle. For clear shots at short range they are great.
308 and most of its variants are all you ever need for deer.