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 …

5.56mm cartridges are ideal for target shooting, home defense, and varmint hunting. Their lightweight design allows for quick follow-up shots and mild recoil, making them accessible for …

Oct 23, 2025 · 223 vs 556: What’s the Difference? The cartridge cases of the 223 Rem and 5.56 NATO appear identical on the outside, but 556 cases can have minutely thicker case walls.

5.56 AR15 rifles for sale online or in-store at Sportsman's Warehouse. Shop a full selection of 5.56 caliber AR15 rifles from top firearms manufacturers.

Take a look at our selection of .223 Remington and 5.56 NATO ammo from top manufacturers. We carry the best .223 Rem and 5.56mm ammo on the market.

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Renowned for accuracy, reliability, and consistent performance, our carefully curated range of 5.56 Ammo features industry-leading brands such as Armscor and Winchester.

Oct 30, 2025 · 556 ammo, officially known as 5.56x45mm NATO, is a rifle cartridge developed in the late 20th century for military and civilian use. It is the standard round for the AR-15 and …

5.56x45 ammo derived from the .222 cartridge and was officially adopted as the standardized NATO round in 1963.