If you are a modern sportsman looking to enhance your collection, or a beginner trying to find a great starting point to build that dream AR-15 rifle you have been wanting. Then the Expanse M4 from Colt is a great way to add a quality rifle that you can count on to the stable. Chambered in 5.56x45 NATO with a 16" barrel with 1:7 twist. Adjustable stock. Thirty round aluminum magazine. A2 Front Sight and Flat Top Upper Receiver are ready for the addition of Optics, Carry Handle, or Rear Iron Sights. Complete Upper Receiver that now includes Forward Assist and Dust Cover.