See title. Specifically for the "high power, bolt-action rifle with a variable-power, magnified optic" mentioned in the 5 guns post , complimenting the other guns mentioned there. If you could only have one, which would it be? I know the answer is always "it depends", but what is your thought process in deciding and what works best for your needs?
The top options to look at are .308 Winchester, .30-06 Springfield, 7mm Remington Magnum, .300 Winchester Magnum, and 6.5 Creedmoor.
It really does depend on your intended use with choosing one of these. Keep in mind that the differences in power and ballistics is almost negligible for most situations. For instance, 7mm and .300 Win Mag pack the most punch. 7mm has a slightly flatter shooting trajectory past 600yds. 6.5CM and .308 pack the least punch (6.5CM slightly less). 6.5CM has the flattest shooting trajectory of all of the calibers listed. .30-06 is in the middle in terms of power, but has arguably has the worst ballistics of all of them. .308 and .30-06 are the oldest cartridges and thus can be easily found everywhere. 6.5CM is the youngest. .308 and 6.5CM can fit into short-action rifles, so you can find lighter rifles to carry around (and some as AR platforms). All of these cartridges can hit a plate at 1000yds with practice.
Which one of these cartridges you choose depends on what you want to use it for. Hunting (medium game? big game? desert hunting? mountain hunting? thick forest? different recommendation depending)? Self-defense? Maximum long range?
Makes sense, good info. There's a reason all those cartridges exist but I'm not at the stage where I can narrow down my shooting activities enough to accordingly min/max my cartridge choice. I didn't realize that both 6.5 and .308 have the benefit of being usable in short action rifles and others do not.