You can find the Spike's Tactical 5.56mm M4 LE 16" Upper 9" BAR Rail here.

Spike's Tactical makes quality AR-15s at affordable prices. The 5025-R9S is a Mil-Spec upper with an M4 16" 1:7 twist chrome-lined barrel chambered in 5.56mm/.223 and an A2 flash hider. This model has a carbine-length gas system, ST Micro Gas Block, .750" Diameter Gas Seat, 9" ST BAR Rail System, and an M16 bolt carrier group.

The upper receiver is CNC machined from a 7075 T6 MIL-H-6088 forging with Type III Class 2 Hardcoat Anodized Finish, has extended M4 feed ramps, Picatinny Rail on the top, and comes with a forged Mil-Spec Charging Handle. The barrel is made of certified MIL-B-11595E Chromoly Vanadium steel, is individually High Pressure Tested (HPT) and then individually Magnetic Particle Inspected (MPI), and has a MIL-STD-171 Phosphate Finish. The M16 Full Auto Bolt Carrier Group is shot peened, individually High Pressure Tested (HPT), and then individually Magnetic Particle Inspected (MPI), and is phosphate coated. Backed by the Spike's Tactical Lifetime Warranty.