Ammo & Calibers

.223 Remington vs 5.56 NATO (5.56 x 45mm)

We have alot of customers that ask us what is the difference between the .223 Remington caliber and the 5.56 Nato caliber. They are concerned about which ammo to buy and which they can shoot safely in their rifle. We are going to explain the difference.
The common mistake people make is that they think the two are the same.  5.56 Nato and .223 Rem are in the same family, but still different. This can be a problem and lead to a dangerous situation. The case dimensions are the same, but there are enough other differences that make the two not completely interchangeable.
One big difference is pressure. Another big difference is length. 5.56 Nato , or 5.56 x 45, is slightly larger than a .223 Remington.

Customers ask what is safe? It is safe to shoot .223 Remington cartridges in any safe gun chambered for 5.56×45 mm. But also, it is not recommended and it is not safe to shoot 5.56×45 mm cartridges in a firearm chambered for .223 Rem.

When shooting .223 Rem. cartridges in a firearm chambered for 5.56×45 mm, it’s likely the shooter will lose accuracy and muzzle velocity.

What does this mean to you? If you have an AR-15 rifle chambered in 5.56×45 mm, you can shoot either .223 Remington or 5.56×45 mm safely. If your barrel’s twist rate is 1:7″ you should use bullets weighing 60 grains or heavier. If you have any rifle with a 1:12″ barrel twist you should use bullets of 60 grains or less for best accuracy. If you have a .223 Rem. rifle of any type, it is not recommended and not safe to use 5.56×45 mm ammo.

Leave a Reply

Your email address will not be published. Required fields are marked *