Rock River Arms 450 Bushmaster Mid A4 Upper 16 Stainless 13in MLOK

The Rock River Arms 450B0461 450 BM MID A4 UPR HALF SS UPPER delivers a high-performance complete upper designed for serious shooters seeking reliability and precision in a versatile upper receiver assembly. Built around a 16" heavy stainless steel barrel threaded for rugged durability, this upper is chambered in 450 Bushmaster and features a 1:24 twist to stabilize a broad range of projectiles for dependable performance at practical hunting and target distances. The black receiver and 13" M-LOK handguards provide a clean, rugged platform for accessory compatibility and rapid adapter installation while maintaining a balanced, rifle-length profile ideal for mid-range engagements. This upper is crafted to pair seamlessly with compatible lowers to create a dependable platform that excels in hunting scenarios, from game entries to field shooting, thanks to its robust construction and corrosion-resistant finish. The combination of the half-SS upper, stainless steel barrel, and precision machining ensures consistent alignment, smooth cycling, and repeatable accuracy, making it a reliable choice for shooters who demand performance in a compact, ready-to-build package.