There are endless stories of deer being killed with a rifle chambered in .22 LR. So if a little .22 LR is sufficient to kill a deer, why do we need anything more powerful? Isn’t .243 Winchester good enough? Isn’t .30-06 Springfield good enough? Why do we need this big-ass rounds like .300 Win Mag, and 7mm magnums? It’s not like they can make the deer any more deader.

Basically, shooting at longer distances.

An article from Field & Stream on the topic.

High velocity by itself does not kill anything, nor does it kill anything faster than standard velocity.

I started out believing devoutly in lots of speed, but 40 years later, having shot creatures of all sizes with just about everything that goes bang, I’ve never been able to find any correlation between bullet speed and sudden animal demise.

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Not only do super-speed cartridges not kill any faster, but there are distinct disadvantages to them as well. First, let’s consider recoil and muzzle blast…. Second, when you get bullets traveling at 3000 fps and over—these days, way over—even the strongest and slowest-expanding of them makes a mess of whatever it hits…. Third, barrel life for the super-speed cartridges is considerably shorter than it is for standard-velocity loads.

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Given all these drawbacks, why is it that high velocity keeps getting higher, and new and horrific super loads keep appearing? Because nothing makes hitting at long range easier than a good dose of feet per second. If you think you will need to take a shot at 300 yards and over, high velocity is your very best friend.

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However, speed alone will not solve all your problems in hitting at long range. You also need resistance to wind drift and momentum, or the ability to sustain velocity way out there. The way you get it is by going not to light bullets that give the highest initial velocity—but to the heavier slugs in a given caliber, and to bullets that are streamlined.

So what it comes down to is context and selecting the appropriate tool for the context. If you’re out hunting big elk in the Rockies, 300 yard or more shots are likely and so a big gun helps. Here in Texas, 200 yards might be the extent of it and consider I’m working on a .223 Remington load for Texas whitetail and feral hogs. Heck, my father-in-law, who is a lifetime hunter, says that he’s tried just about everything out there over the years and he finds the .25-06 about the best thing for Texas hunting.

Like all things in life, you can pick the wrong tool for the job and still get the job done. But picking the right tool for the job often yields to the best and most satisfactory end results.