.223 Remington

From left: .222 Remington, 223 Remington, and 5.56×45mm NATO

The .223 Remington (.223 Rem) is a type of firearm cartridge. It is the most used cartridge for AR-15 type rifles.

.223 Remington Media

• 

  .223 Remington maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

• 

  (Left to right) .223 Remington, .243 Winchester, .308 Winchester