Pro2a Tactical offers a large selection of 300 Blackout AR-15 Upper Assemblies. 300 Blackout is the perfect caliber for short/medium range applications and is the perfect round to be suppressed. We offer the 300 Blackout in a variety of barrel lengths, twists and formats to suit your needs. All of our uppers are assembled by the most experienced armorers and covered by our limited lifetime guarantee.