223 Wylde/5.56 NATO

The Wylde's hybrid chamber was designed to exploit the accuracy advantages of the .223 Remington chambering without problems concerning over pressure or compromising the functional reliability of semi-auto firearms like the AR-15 family when using 5.56×45mm NATO military ammunition. Coincidentally, it shoots the relatively long and heavy 80-grain bullets commonly used in the Sport Rifle Competition very well and is one of the preferred chambers for that use. The Wylde chamber is used by rifle manufacturers who sell "National Match" configuration AR-15 rifles, barrels, and upper receivers.