Rock River Arms has earned a reputation for crafting high-quality firearms trusted by military, law enforcement, hunters and shooting enthusiasts of all disciplines. Their complete upper receivers are an excellent choice for finishing a rifle build or swiftly changing calibers on your favorite AR-15. This complete upper receiver is equipped with a .223 Wylde chamber, optimized for both 5.56x45mm NATO and .223 Remington ammunition. It features an 18 inches stainless steel heavy match barrel complemented by a muzzle brake, enhancing accuracy by reducing felt recoil for smoother follow-up shots. The upper includes a lightweight aluminum free-float handguard with M-LOK slots, allowing easy attachment of M-LOK compatible accessories such as bipods, foregrips and lights. Additionally, it comes complete with a bolt carrier group and charging handle, making it ready-to attach to any standard AR-15 lower receiver.