You can order a Bushmaster 20" government profile 1/7 twist.
You can buy the BCM upper, like I did.
Or, you can order the Palmetto.
Link
Barrel: 20", 4150 Steel, Government style profile, 5.56 NATO chamber with a 1:7 twist , chrome-lined, lead-lapped and air-gauged bore, rifle-length gas port, and M4 feedramps. Barrels are finished off with a taper pinned, f-marked, front sight post, standard handguards, and an A2 flash hider.
Upper: Forged 7075-T6 A3 AR upper is made to MIL-SPECS and hard coat anodized black for durability. Featuring machined T marks, and a mil-spec finish. These uppers are made for us right here in the USA by a mil-spec manufacturer, and are marked with the Palmetto State Armory logo on the left side, up front, just below the rail.
Bolt: Bolt is made of Mil-spec Carpenter 158 steel, Shot peened, MPI and HPT. Gas key is secured with grade 8 fasteners and staked per mil-spec. Bolt carrier is parkerized outside, chrome lined inside, and laser engraved with the Palmetto State Armory logo
Each upper is assembled to order with care. Please allow allow 7 business days for your upper to ship.
Pricing: $409.95 ea