223 Rem. as a dedicated service rifle cartridge by FN about 20 years later. Today, it’s common to see rifles chambered for both, especially AR-15 variants. And it is equally common to see ammunition ...

223 caliber ammunition—a high-velocity, military-standard rifle ammunition often used in AR-15-style rifles—and a handgun ammunition magazine to a first-time customer, Platkin said.

John B. Snow Getting this rifle up and running couldn’t be simpler. Just stuff some .223 ammo in the 10-round polymer P-Mag that comes standard, seat the magazine, cycle the lever, and you’re ready to ...

223 Rem. Tyler Freel Lots of 5.56 NATO ammunition is commercially available, and as a universal solution to the discrepancy between 5.56 and .223 chambers, several rifle manufacturers began ...