What caliber is an AR-15?

AR-15 rifles are chambered in many various calibers and are known for their versatility. The most common calibers for an AR-15 are 5.56x45 NATO and .223 Remington. These calibers are very similar and are often used interchangeably in AR-15 rifles.

It is important to remember that the AR-15 platform can be chambered in many other calibers including .300 Blackout, .224 Valkyrie, 6.5 Grendel, and much more. The choice of caliber depends on factors such as intended use, preferences, ammo availability, and legal restrictions. It is always important to use the correct ammunition specified for your particular AR-15 chambering.