Here are some pics of one I just put together. The only thing lacking is the flash suppressor and sights. I've only run five rounds through it for a function check as fast as I could squeeze the trigger, with nary a hiccup.
Stiller Precision Predator XT Billet Lower
VLTOR MUR-1 upper
18" Black Hole mid-length barrel
Geissle SSA-E trigger
Spike's Tactical BCG
13" Troy Tactical Hand guard
Bravo Company Gunfighter Charging handle
Have some Coyote Alumihyde en route for the grip and buttstock.