5.56 NATO & .223 Wylde AR-15 Upper Assemblies

5.56 NATO & .223 Wylde AR-15 Uppers by Barrel Length

Shop 5.56 NATO and .223 Wylde AR-15 uppers from Moriarti in a wide range of barrel lengths, handguards and finishes. Browse everything from micro ARP and AR pistol uppers to 16-inch carbine and long-barrel rifle configurations. Choose from 5.56 NATO and .223 Wylde chamberings for recreational, target and general-purpose AR-15 applications. Compare each upper for exact barrel length, twist rate, gas system, rail and included components.

What is the difference between a 5.56 NATO upper and a .223 Wylde upper?

A 5.56 NATO upper uses a 5.56 NATO chamber, while a .223 Wylde upper uses a hybrid chamber designed to safely accommodate both 5.56 NATO and .223 Remington ammunition while incorporating chamber geometry intended to support accuracy with .223 ammunition. Always follow the ammunition and specifications listed for the individual barrel.