Windham Multi-Caliber Bug-Out Bag, Semi-automatic, Multi-Caliber System, RMCS Lower Receiver with .223 & 9mm Interchangeable Magazine Wells, RMCS Upper Receiver with Fixed Quad Rail Forend and Barrel Locking Mechanism, 2 Barrels: 16" 223 Rem/556NATO M4 Profile, Out of stock. Check back later... $2,451.00