Many thanks for everyone's input. The number of widely varying experiences and thoughts are the reason I come to this forum.
About the barrel: Two reasons for considering a bull barrel in 16" only, sporter profile for almost all others. First is repeatable accuracy out to 300 yards. Just how much difference in accuracy can be expected between the two 16" barrel profiles. While the kill zone may be 12", an anchoring shot is far more appropriate in the often dense and mountainous areas I hunt. Far better to use a second shot on an animal that's not getting away than trying one deadly shot on animal that may run over the other side of the mountain and never be found. The second consideration, and far less important, is overall balance and how comfortable will it be for me to carry and use.
Concerning actions: Tirod's reply is very insightful. However, my experience with scopes on anything bigger than a 22LR or .204 Ruger is recoil keeps me from seeing where shots are hitting. The type of action determines the effort and time working it, hence how long before the process of re-acquiring the target may occur. Naturally, a semi-auto will be much quicker than a bolt, lever, pump, etc and those much faster still than a single shot. Which, by the way, is still much faster than my muzzle loader. Reducing the overall length and weight of the gun is more important than the type of action. Also, the type of action may very well determine how much stock has to be carried.
Caliber. I haven't heard much and am a bit surprised. With the AR platforms there are three realistic options: 6.5 Grendel, 6.8 SPC, and .458 SOCOM. Any experiences and are any of these truly viable? Remember, the first shot has to anchor the animal. From the bolt action bunch, It is the very fine .308 cartridge. I want to check out the Ruger Predator, thanks jmr40 and BTW that is one fine gun, as well as a few others mentioned. What of the many choices available in the single shot category? I can consider the versatility of hand loaded light loads for the 375 H&H or factory 7mm-08, trading my muzzle loader for a T/C barrel, pistol hunting deer with 30-30, as well as a turkey barrel.
Price: Not more than 550 dollars as carried up the trail. That includes scope, ammo, sling, everything. Excepted is the T/C as that I would order as a pistol frame so I can pistol hunt as well as upgrade to a very fine muzzle loader for free. And let's not forget the gimmickry of the manufacturers. Plastic stocks are far cheaper and less time consuming to produce. The same is true of stainless. No time consuming bluing, EPA conformance for chemical disposal, etc. And when was the last time anyone has seen really good bluing on a factory standard firearm?
A bit on my changing hunting style. Last year, just for fun, I took my old single shot 12 gauge turkey hunting. SO much better to carry. It started me thinking. This year I went scouting with my 5 1/2" Super Blackhawk loaded with snake shot and fully realized just how carrying an 36" long, 8+ pound ultimate killing machine distracts from the joys of hanging about the woods, looking for quarry.
Once again, many thanks to all for all the great replies and input.