Moriarti Armaments offers a range of 300BLK upper assemblies, from complete setups to individual components. Each assembly is meticulously crafted to ensure compatibility, reliability, and optimal performance with your AR-15. Moriarti Armaments offers a range of 300BLK upper assemblies, from complete setups to individual components. Each assembly is meticulously crafted to ensure compatibility, reliability, and optimal performance with your AR-15. Moriarti Armaments offers a range of 300BLK upper assemblies, from complete setups to individual components. Each assembly is meticulously crafted to ensure compatibility, reliability, and optimal performance with your AR-15. Moriarti Armaments offers a range of 300BLK upper assemblies, from complete setups to individual components. Each assembly is meticulously crafted to ensure compatibility, reliability, and optimal performance with your AR-15.