Sons of Liberty delivers one of the rigid upper receivers on the market with the Broadsword-89. These uppers are available in .223 Wylde, 5.56 NATO, and the flat shooting 6mm MAX, and come in a wide assortment of barrel lengths. All Broadsword-89 Uppers feature an extended barrel nut, Drivelock tensioning crossbolts, and a Sons of Liberty 89 series rail. Additionally, the anti-rotation tabs and stainless steel center index dowel allows users to transform almost any lower receiver into a match grade rifle. Features of the Sons of Liberty Broadsword-89 Upper Receiver: Available Calibers: .223 Wylde & 6mm MAX Available with multiple barrel lengths Extended barrel nut Drivelock tensioning crossbolts Sons of Liberty 89 series rail Sons of Liberty Gun Works SOLGW M4-L89 Broadsword 5.56mm 12.5" No BCG/CH Upper Receiver M4L89BSUPPER-12.5-556