This is Larry Vicker's M4 Carbine he used in Delta.
3 Barrel Options:
- 14.5 Inch 1/7 Twist Chrome Lined, Phosphate Finish
- 14.5 Inch 1/7 Twist Chromed Lined, Phosphate Finish Pencil Barrel
- 16 Inch 1/7 Twist Nitride M4 Profile Barrel- This will both save you money and allow you to run as a barrel since it is 16 inches.