The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, commonly pronounced "five-five-six") is a rimless bottlenecked centerfire intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. [5] It consists of the SS109, L110, and SS111 cartridges.

2023年4月19日 · There are two primary differences between the .223 Remington and the 5.56 NATO. The first is that the 5.56 is loaded at higher pressures than the .223. The 5.56 NATO cartridge runs around 58,000 pounds-per-square-inch (psi), while the .223 Remington is loaded to approximately 55,000 psi.

2025年2月5日 · Yes, there is a difference between 5.56 and 5.56 NATO ammunition, albeit subtle yet significant, primarily in pressure and chamber specifications, potentially leading to safety concerns depending on the firearm used.

2023年2月2日 · Here are 5.56 NATO ballistics charts with other information and a brief history on this centerfire rifle cartridge.

2024年2月17日 · Is 5.56 NATO the same as 5.56? No, 5.56 NATO and 5.56 are not the same. While they have similar dimensions and fire the same bullet, the key difference lies in the chamber pressure. 5.56 NATO has higher chamber pressure than 5.56, which means they are not interchangeable in all firearms.

The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO) is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries.[3]

2025年3月7日 · Some modern rifles are marked 223/5.56, indicating that they are built with a 5.56 NATO chamber and can safely fire both types of ammunition. Ammunition usage guidance for chambers which do not follow the standards of SAAMI or NATO/STANAG can only be made by the manufacturer of those firearms.