223 vs. 5.56

The big wide world of ammo can often be a confusing one. There are eight different 9mm
rounds on the market, and none are interchangeable. The 223
and 5.56
rounds are even more confusing, because they are the same, right? Well, no, but kind of? The 223 vs. 5.56 debate has been going on for a long time, but let's put it to bed here.

Cartridge Dimensions and Loads

The 5.56 round was developed from the 223 Remington, so with a lot of guns, the ammo can be interchangeable. 5.56
is a NATO Military load, and the 223 Remington
is a commercial load.

Wolf Performance Gold .223 55gr Premium Grade FMJ Ammunition

A rifle developed for 5.56 is capable of using 223 Remington safely. A rifle designed for 223 Remington should not be used with 5.56 though. Will your gun explode if you do? Maybe, but not likely. The real danger comes from prolonged use of the hotter 5.56 loads, which create more chamber pressure in a chamber designed for the 223 Remington. More pressure means potential damage, so it's best to stick with 223 Remington in 223 rifles. The leade, which is the distance between the case mouth and where rifling begins, is longer in 5.56 rifles. The 223 Remington has much tighter chamber dimensions. This is the big reason why 5.56 rounds can damage 223 Remington rifles.

PMC 5.56 X-TAC 62gr Green Tipped Ammunition

There Are Still Other Differences To Consider

The 223 Remington tends to be a more accurate round. So you may be thinking, well, I'll just buy a 5.56 caliber rifle, that way, I can use both 223 and 5.56! Well, you can, but the 223 is more accurate in 223 caliber rifles only. It won't maintain the same level of accuracy in a 5.56 caliber rifle. The 5.56 caliber is hotter and designed for military use. This means they penetrate better on average at longer ranges. The common 62-grain loads tend to tear through barriers a bit better, and when paired with a 20-inch barreled rifle, they can even penetrate some AR 500 armor plates. Inside the home, these rounds tend to penetrate less because of the close quarter's nature, which reduces the risk of hitting someone due to over-penetration.

The FosTecH Phantom Chambered in .223/5.56

223 Remington tends to be better suited for hunting or long-range marksmanship. The 223 Remington round comes in various hunting loads, with ballistic tips, soft points, and rounds specifically designed for small varmints. Overall there are way more 223 Remington loads available on the market than 5.56 loads.

What If I Wanted the Best of Both?

A new chambering, 223 Wylde, is popular these days. It is a hybrid that was designed by Bill Wylde. The idea is simple. Mix the specifications in a safe way to get the interchangeability of a 5.56 caliber rifle, while accuracy is preserved when shooting 223 Remington loads.

Rock River Arms LAR-15 Predator chambered in .223 Wylde

I honestly don't know of any company producing 223 Remington AR 15s, but a lot of rifles designed for hunting are. This includes bolt actions, single shots, and more. There are some purpose-built 223 rifles like the Mini 14 Target model, which is much different than 99% of Mini 14s. I hope you fine folks learned a thing or two about the 223 Remington and 5.56 caliber rounds. These calibers are the closest thing we have to having two completely interchangeable rounds, but are still highly different, so confusion is normal. Just remember this rule of thumb, 5.56 rifles can use both, but 223 Remington guns can only shoot 223 Remington. Be safe, be smart, and shoot a lot. Shop All .223 Rem Ammunition
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