From a novice's point of view, I see the debate as being distilled to this:
Smaller calibers can be packaged with a lighter rifle, but why not just put a slightly larger caliber in a lighter rifle? Recoil - the idea being that you will practice more with a smaller caliber without beating yourself up...
Okay, but how many rounds are people actually putting through these barrels before they're worn out? Is there a person who will only shoot 40 rounds a year through a 7 PRC because the suppressed/braked recoil is too much for them, but will shoot 800 rounds a year with a 6.5CM, without caring about barrel life?
I'm not convinced those people exist in any meaningful number.
The argument in favor of something like a 6.5CM for a dedicated elk rifle would have to hinge on the following claim: there is absolutely no benefit whatsoever to stepping up to something in the range of a 7 PRC. I'm not yet convinced that this is a sound claim.
The relevant question isn't whether these smaller calibers can kill elk, it is a question of tradeoffs, as always. If you want more range time, you can always practice with something other than your hunting rifle, if it's shooting fundamentals you're honing. Of course there is no replacement for practice with the rifle you'll be carrying in the field, but there is value to practicing in general.
First and foremost....People should just shoot whatever they want. Shot placement and bullet choice is going to determine the outcome. Big, small, medium....whatever....
The idea isn't necessarily that you will practice more with a smaller caliber. But that the smaller caliber is easier to shoot, regardless of how much you practice. Less recoil equals more accuracy for 99.99999% of shooters, and equals faster follow up shots for the same. Obviously you can mitigate recoil with rifle weight also. But the point still stands.
Barrels wearing out on a 6.5CM isn't much of a worry for most people. Unless your shooting something pretty spicy, your probably gonna get around 3K rounds anyways.
I would agree that overall its a pretty small percentage of people that shoot heavy volumes of hunting rifles rounds if the rifle is say above 6mm, unless they competitively shoot, or really at all.
The "argument" - "
there is absolutely no benefit whatsoever to stepping up to something in the range of a 7 PRC".
As long as you are shooting at a range in which the bullet you have chosen has enough velocity to properly work. And you have chosen a bullet that is going to do the job. The statement is absolutely true. And not really arguable at this point. There are bullets out there that I would personally never shoot an elk with out of a 6.5 creedmoor, because I would be worried about the pure resulting carnage, killing it is objectively not a concern at all.
The only potential tradeoff is effective range.....That 7 PRC might get you out past 1,000yds. The creedmoor may only be good for 700yds or something.
If your inside 500 yards or whatever, your giving up nothing at all. Realistically in an objective sense only downsides to going to that 7PRC. More recoil, more potential meat damage, more expensive ammunition, more expensive to reload.
People choose whatever they choose for various reasons....nothing wrong with the choice. But going bigger is just a mental conditioning thing at this point. Unless, we are talking about shooting waaaayyy out there range wise. Or just simple personal preference....cool.