Externally the .223 Rem. and the 5.56 NATO are identical but military 5.56 NATO brass has slightly thicker walls.
5.56 NATO ammunition is also loaded to a higher pressure than .223 Rem. Why I dont know. Everybody that shoots ARs knows AR-type rifles with a 5.56 NATO or .223 Wylde chambers can fire 5.56 NATO and .223 Rem. ammunition interchangeably with no pressure problems. Firing 5.56 NATO ammo in a rifle with .223 Rem. chamber can lead to extraction problems and blown primers.
The real difference is in the chambers or the throats are cut in the respective rifles. The free-bore in the 5.56 NATO is
.0303 inch longer and .0025 inch larger in diameter than that of a .223 Rem. Also, the angle at which the rifling begins-the point from were the lands start to where they establish a bore diameter of .219 inch-is at a 2-degree shallower taper in a
5.56 NATO rifle. These were incorperated into military rifles to improve reliability in extremely dirty combat conditions, where stopping to clean a gun may not be an option.
For example, after firing several hundered rounds of some ammo brands thru an AR chambered for the .223 Rem. , the sealant on the ammo can build up in the throat and prevent a round from fully chambering. The longer throat of a 5.56 NATO chamber prevents this.
The 5.56 NATO military cartridge that is nothing more than a hot-loaded,or +P version, of the .223 Rem. Some manufactures offer a "hybrid" chambering called .223 Wylde, which is a compromise of throat dimensions between the 5,56 NATO and
the .223 Rem. Some people think that the longer throat in the
5.56 NATO chamber might not provide th accuracy you would see in a rifle chambered for .223 Rem or .223 Wylde. I dont know I never had the chance to test them side by side but if there is a difference it cant be that big. Also, if you are hand loading for the 5.56 NATO it makes no difference when following the .223 Rem load data- from a handloading standpoint,they are the same cartridge.
There are some facts im sure I missed but I think I covered the main ones.
5.56 NATO ammunition is also loaded to a higher pressure than .223 Rem. Why I dont know. Everybody that shoots ARs knows AR-type rifles with a 5.56 NATO or .223 Wylde chambers can fire 5.56 NATO and .223 Rem. ammunition interchangeably with no pressure problems. Firing 5.56 NATO ammo in a rifle with .223 Rem. chamber can lead to extraction problems and blown primers.
The real difference is in the chambers or the throats are cut in the respective rifles. The free-bore in the 5.56 NATO is
.0303 inch longer and .0025 inch larger in diameter than that of a .223 Rem. Also, the angle at which the rifling begins-the point from were the lands start to where they establish a bore diameter of .219 inch-is at a 2-degree shallower taper in a
5.56 NATO rifle. These were incorperated into military rifles to improve reliability in extremely dirty combat conditions, where stopping to clean a gun may not be an option.
For example, after firing several hundered rounds of some ammo brands thru an AR chambered for the .223 Rem. , the sealant on the ammo can build up in the throat and prevent a round from fully chambering. The longer throat of a 5.56 NATO chamber prevents this.
The 5.56 NATO military cartridge that is nothing more than a hot-loaded,or +P version, of the .223 Rem. Some manufactures offer a "hybrid" chambering called .223 Wylde, which is a compromise of throat dimensions between the 5,56 NATO and
the .223 Rem. Some people think that the longer throat in the
5.56 NATO chamber might not provide th accuracy you would see in a rifle chambered for .223 Rem or .223 Wylde. I dont know I never had the chance to test them side by side but if there is a difference it cant be that big. Also, if you are hand loading for the 5.56 NATO it makes no difference when following the .223 Rem load data- from a handloading standpoint,they are the same cartridge.
There are some facts im sure I missed but I think I covered the main ones.
