Introduced only two years apart, the .223 Remington and the .243 Winchester couldn’t have come from more different neighborhoods of the firearms world.

The .223 Rem. is a classic Army brat. It was developed in 1957 for an experimental rifle known as the AR-15. That gun’s modern military counterpart, the 5.56 NATO, has been in continuous use by militaries around the world since the early 1960s.

The .243 Win. was developed by Winchester in 1955 for use in its Model 70 bolt-action and Model 88 lever-action rifles. It’s a small-to-medium sized game caliber whose primary use has been taking down four-legged rather than two-legged critters.

But your past doesn’t define you, and it doesn’t define these calibers either. For many hunters, the .223 Rem. and the .243 Win. are synonymous with both deer and varmint hunting, so we decided to pit them against each other to see who comes out on top.

Ballistics
Ballistically speaking, these calibers would be cousins rather than brothers. The .243 Win. is a necked-down .308 Win., so it holds nearly twice as much powder as the .223 Rem. Added powder increases velocity and energy, which translates to what the Internet calls “knock-down power” (more on that later).

A .243 Win. can push a 75-grain projectile about 3,300 feet per second at the muzzle and achieves about 1,800 foot-pounds of energy. A .223 Rem. by contrast achieves only about 1,400 foot-pounds of energy by throwing a 75-grain projectile 2,900 fps.

It’s true that bullet construction and shot placement will kill an animal more effectively than poor shooting with a huge caliber. Still, when comparing cartridges, foot-pounds of energy is a helpful way of describing the weight of a projectile and how fast it’s moving. Generally speaking, a heavier bullet travelling faster will give you a better chance of putting down an animal. In this comparison, the .243 Win. wins hands-down.

Maximum effective range is another way to compare one caliber to another. This is usually achieved by determining the maximum range at which a bullet has retained enough velocity to fully expand.

Generally speaking, (very generally; calm down, everyone) a .223 Rem. can maintain enough velocity to take varmint and medium-sized game out to 250 yards, or the distance at which the bullet is still travelling about 2,300 fps, according to Frank C. Barnes’ “Cartridges of the World.” But that range doesn’t apply to every bullet. Federal’s 55-grain Trophy Cooper, for example, has a minimum velocity for full expansion of only 1,800 fps. That extends the maximum effective range all the way to 350 yards, depending on your velocity at the muzzle.

The .243 Win. can reach out even further. Federal’s 85-grain Trophy Copper also has a minimum velocity of 1,800 fps, and it’s still cooking along at that speed well past 500 yards.

I’m not saying your .243 Win. load will reliably kill a deer out to 500 yards. I’m also not saying your .223 Rem. can’t kill a deer past 220 yards. True “knock-down power” depends on your bullet’s construction and minimum velocity, your cartridge, and your barrel length.

But for purposes of this comparison, I’d give the edge to the .243 Win.

Winner: .243 Win.

Shootability
“Shootability” is a broad term we’re using to mean “how available is this caliber and how comfortable is it to shoot?”

In a normal year, the .223 Rem. would be the clear winner. When it comes to availability, it’s always good to bet on the NATO caliber. With dozens of countries relying on the .223/5.56 to arm their infantry, there’s usually plenty of it to go around.

But this is not a normal year. Federal lists only two .223 Rem. cartridges as “available” to order online: the 53-grain Varmint and Predator and the 69 grain Gold Medal Match. The prices on Federal’s website don’t appear to have risen, but elsewhere I’ve seen .223 Rem. double in price. Where before this year you could find .223 Rem. for about 30 cents per round, now you’ll be lucky to find anything in stock below 60 cents.

By contrast, six of Federal’s 17 .243 Win. cartridges are currently listed as available. You’ll probably pay twice as much per round as .223 Rem., but at least you’ll have something to shoot.

In 2020, .243 Win. wins the availability battle. In non-pandemic times, the .223 Rem. wins in a landslide.

In terms of comfort, the .223 Rem. is the obvious winner. The .243 Win. isn’t uncomfortable, but compared to the .223 Rem., it’s snappy (depending on your rifle, of course). As Chuck Hawks notes in his great recoil table, the .223 Rem. produces about half the felt recoil of the .243 Win.

Since this year is such an anomaly (I hope), I’m going to give the overall nod in this category to the .223 Rem.

Winner: .223 Rem.

Versatility
“Versatility” refers to both range of bullet weights available and range of actions chambered in a specific cartridge.

Barnes lists 12 bullet weights commercially available for .243 Win., ranging from a 55-grain boat tail to a 105-grain hollow-point boat tail. The majority of the cartridges use bullets ranging from 85 to 105 grain, and Federal’s offerings follow that trend.

The .243 Win. was designed as both a light deer rifle and a varmint cartridge—it can hold its own against high-velocity .22-calibers but still provide enough oomph to take down larger animals. A 55-grain or 75-grain Nosler Ballistic Tip or Hornady V-Max bullet would do great work against varmints while a 100-grain Sierra Game King could take down any whitetail in North America.

The .223 Rem. has slightly less range in terms of bullet weights (40 grain to 75 grain), but it covers basically the same ground. It’s better suited for varmint hunting than big game hunting, but a 62-grain Fusion or even a 55-grain Trophy Copper would reliably take down a whitetail given proper shot placement.

You can find lever, bolt, and semi-auto rifles chambered in both actions. The latter two are more common, but Henry makes a sweet lever gun called the “Long Ranger” in both calibers. The AR-15 chambered in .223 Rem. is the most popular rifle in America, and Weatherby offers tack-driving bolt guns in both calibers in a wide variety of configurations.

I’d call action availability a draw. If you’re looking for a semi-auto, you’ll likely have better luck finding a .223 Rem., but lots of companies chamber semi-auto guns in .243 Win. as well. Every major manufacturer makes a bolt gun in both calibers, so that’s not a distinguishing factor.

Winner: Draw

And the Winner Is…
Ballistics, as they say, are king, so I’m giving the ultimate nod to the .243 Win. I like having the extra power and range for medium-sized animals, and I don’t see much downside for varmint hunting. The ammunition is more expensive, but it’s just as common (especially these days), and I can find rifles in lots of different actions and from many different manufacturers.

Overall Winner: .243 Win.