.300 Blackout is an intermediate cartridge developed in the USA for use in the M4 carbine. The cartridge has increased performance in shorter barrels and effective subsonic performance for silencer use when compared to 5.56mm NATO. It also has superior stopping power than 5.56 NATO, especially at closer ranges, making it a suitable cartridge for many hunting and defensive applications.
Our 300 Blackout uppers all come with a 100% satisfaction guarantee. Our complete upper receivers also come with charging handles, gas systems, bolt carrier groups, and other parts needed to complete a build for an AR platform. We also sell .300 Blackout build kits. Check them out here and if you have any questions, please reach out to our customer service team at 239-848-6757.