There's an interesting discussion going on over at the Nation of Riflemen forums about the utility of various magnum rifle calibers.
The last five years have seen the re-introduction of half a dozen old magnum chamberings, and probably two dozen new one's, almost all of them in the sub .300 caliber category. Realistically, I don't think theres any ballistic advantage to any of them, because all they are really doing is taking a fatter case, making it shorter, and necking it down further to get the same results as existing calibers (magnum or non). This is supposedly more efficient, and it allows for a slightly smaller gun (by about 1/2" or so, or 1" for the ultra short magnums), but again, where's the utility in these chamberings?
To my mind, if you can't take it with a .270, a .308, or a .30-06, then you can't take it with a 7mm, or any of the .2xx or 6.x magnums.
Welllll...... except some of the semi-wildcats like lazzeronis. He makes a 6.53mm (.257) magnum that puts a 120 grain bullet out to about 4000fps, and that will give you some RANGE. Basically he takes a .375 mag case and necks it down to take a .257 Roberts bullet. Of course it's still only a 120gr bullet so I'd still worry about an Elk or bigger with it; really it's just going to make the longer range shots on medium game safer.
And that's pretty much it right there; honestly, that's the only benefit I can see from the smaller magnums.
Now, once you get into the .300 and above magnums, that's a different story. They carry some respectible bullet weights, at very high velocities; but you pay for it in recoil, gun wear, and ammo price.
With a large magnum, you also lose the ability for quick followup shots, unless you really are a recoil Rhino (I AM one). The felt recoil of a .300 win mag, is SIGNIFICANTLY higher than a 7mm magnum, and the 7mag is; generally speaking; where most people start to say "ouch, I don't want to shoot that again".
I'm ashamed to admit I don't have a hunting rifle right now, (though I'm sure my M14 could do an admirable job of it). When I buy new hunting rifle, I wan't something light weight, but in a respectible caliber, that I can throw over my shoulder for hunting in the scub hills and pine forests of the mountains of northern AZ, Utah, New Mexico, and Colorado (the places it will be easy for me to hunt). You have a mix of LOOOONG range shots (I know guys who take 600+ yard shots every season), and under 100 yarders here, because the terrain is so varied.
My first choice is probably going to still be a .308 here (for ammo commonality and availability), though I have a strong attachment to the .270; but in either case, I'd want to keep my shots to 300 yards, and I don't think I'd use them on elk. Yes a .30-06 is going to give me more bullet weight options than either, but I have a lot of experience shooting the .308, and the .270 at medium game at 300-400 yards; I DON'T have a lot of experience with the '06 at anything like long range.
I think my number choice for MY mountain rifle is going to come down to something like a Remington 700 mountain rifle, a Winchester Model 70 featherweight, or a Weatherby Vanguard Sub-MOA ; or maybe if I can afford it, a Rem 700 Titanium . I'll be going for a matte stainless, matte blackened stainless if possible, and a composite stock, because I want all weather utility, and something damned near indestructible.
Basically all of these guns are available in... well just about any caliber I want, thoguh some versions arent in some calibers etc...
If I decided to go for elk, I'd probably still go for a nice lightweight rifle, but I'd pay the recoil and ammo cost penalty, and move into a 7mm mag. Yes, the .270 and .308 CAN and have taken many Elk, but I'd want jsut a LITTLE more insurance, just in case. In this class are also the .270 short magnums, and those seem like they may be useful choices, but I dont really see any advantage over the 7mag; where they share bullet weights (up to about 150gr), the .270 has a 10-40fps advantage, but the 7mm has factory loads available up to 175gr.
Anything MORE than the 7MM, would really be overkill. You don't need a .300 win mag or a .338 for Elk (unless you want to go out past 600 yards), and there's nothing bigger than an elk that I'm going to be hunting. Really the only reason I'd even consider the 7mag is for the extra 100 yards of safe range it's going to give me on a beast the size of wapiti.
A .308, or a .270, or an '06 for that matter (with a hot 200gr load for example) would probably do the job just as well up close; but you dont often get the chance to be within 300 yards without spooking the bastards, so that extra range is useful for Elk.
I think the biggest caliber I'm going to pick for game is the .300 win mag; and really I can't see a situation where I would be able to use it's additional capability over other options. If I were a tac team sniper I'd seriously consider it, and the .338 lapua magnum; becuase they are the ideal sniper cartridges at extended range, but I know my limitations. I wouldn't feel comfortable taking a shot on a deer or elk sized animal at over 600 yards; which is the farthest I've ever made a kill at, and also the farthest I can reliably shoot out to with good optics. I've made 800 yard shots on static targets; and even 1000 yard shots, but those are far more luck than anything else. I wouldn't ever consider making an 800 yard shot on game.
I can slow my heart rate and breathing down sufficiently, but I'm just simply not that still. The guys who can make those shots all day long are inhumanly still in their muscle and nerve structure.
Realistically, unless you are hunting bighorn at 500+ yards in high plains, or taking long mountain shots (and they ARE fairly common here in AZ, but I'm not going to be taking them); or of course going after Ursus Horriblus; I just don't see the need for anything over a .300 win mag anywhere in North America.
