American Tactical MilSport Lower Features The American Tactical MilSport lower receiver is the serialized heart of an AR-platform rifle chambered in .300 AAC Blackout finished in black to match standard mil-spec furniture and components. Because the lower is the legally serialized part of the firearm it is the piece a builder must start with before adding an upper barrel and stock to complete the rifle. American Tactical designs the MilSport line around mil-spec dimensions so the receiver accepts a wide range of standard AR-15 parts and accessories without requiring proprietary fitment. This compatibility keeps the MilSport flexible for builders who want to mix and match components from multiple makers as they finish out their rifle. The black finish on the MilSport lower resists wear and corrosion through repeated handling and range use which matters on a receiver meant to anchor a long-term build. American Tactical has built its name on delivering functional affordable AR components that perform reliably without the premium price tag of boutique parts. Pairing a MilSport lower with a quality .300 AAC Blackout upper gives builders a complete purpose-built rifle for short-barrel performance and subsonic versatility. The American Tactical MilSport lower is available for sale at GrabAGun for shooters and builders looking to start a dependable .300 AAC Blackout rifle project. American Tactical MilSport Lower Specifications Manufacturer: American Tactical Model: MilSport Caliber: .300 AAC Blackout Color: Black Material: Steel Compliance Firearm Pattern: AR-15 Available At: GrabAGun