I know this is another one of those questions that is like opening a can of worms because so much I’m sure is personal preference.
After reading the threads you provided, One question I did have, is what is the main differences between the ammo you listed? What considerations would you consider making a choice? I never realized there are so many different setup options.
A little terminology:
"caliber" is the diameter of the firearm bore. There can be a huge variation within the same caliber - for example a .308 caliber 30-30 Winchester cartridge is much slower and less powerful than a .308 caliber 300RUM cartridge. Common big game calibers are .243" (or 6mm); .257"; .264" ( or .260" or 6.5mm); .270"; 7mm (or .280" or 284"); .308"; .325"; and .338"
"cartridge" is a specific form factor for a matching piece of ammunition and firearm chambering. For example, .30-30 Winchester, .308 Winchester, 300Winmag, 300RUM, etc. The velocity and ability to drive heavier bullets (and resulting recoil) varies wildly across cartridges that may have the same caliber. Common big game hunting cartridges include .243 Winchester, 25-06 Remington, 6.5 Creedmoor (also called 6.5 manbun on this forum as a friendly teasing of the younger shooters that popularized it), 260 Remington, .270 Winchester, 7mm08 Remington (also called 7mm08Hunttalk on this forum as it is a favorite of Randy - BigFin), 280 Remington, 7mm Remington Magnum, 30-30 Winchester, .308 Winchester, 30-06 Springfield, 300 Winchester Magnum, 300 Winchester Short Magnum (WSM), 300 Remington UltraMagnum (RUM), and 338 Winchester Magnum.
"bullet" is the business end of a piece of ammo. Bullet weight (measured in grains), shape (commonly summarized in its ballistic coefficient - "BC") and make-up (lead, lead with copper jacket, addition of a plastic "ballistic tip", all copper, different ways to bond a lead core to a copper jacket, etc) can result in big differences in "terminal performance" from the same cartridge. For example, a .300WSM cartridge can shoot light 110grain VMax highly frangible bullets super fast but with low penetration and high tissue damage but it can also shoot 180grain solid mono-metal TSX bullets - slower but will penetrate much further and do less tissue damage. Common big game hunting bullet types are "cup and core", "ballistic tips", "bonded", "partition-style" and mono-metal (non-lead) with and without ballistic tips.
"terminal performance" is how the bullet behaves at the point of impact on the animal - this is driven by ability to maintain velocity at the point of impact and the structural integrity of the bullet as it impacts and penetrates the target.
Hopefully with this background, the choices presented in the two link above make a little more sense. For beginners, the 6.5creedmoor and the 7mm08 make great places to start and they are relatively low recoil and capable of taking up to elk at reasonable distances. The .270 and .308 are also good all around options. The 30-06 is a classic all around choice, but in my opinion with modern bullets, it adds no value above the .308, .270 or 7mm08 while adding some recoil.
