The second (and final) Carbine model on the M16A1 Upper Receiver. Used by Alias and Barns in the movie "Platoon", and by Special Forces and Rangers.
- Original length 14.5 inch barrel
- 16 inch barrel as used on the SP1 Carbine
- M16A1 Receiver (with Tear Drop Forward Assist) - US Army
- "Slick Side" Receiver, US Air Force or SP1 Carbine