I went the AR route, too.
Built on a MEGA billet upper/lower set, Jewel trigger with KNS pins, Mike Rock (Rock Creek) blank finished by ABS (16"), YHM free float tube, 3 position (carbine) gas block (port opened to .120)... A1 stock (still playing with the buffer... would like a rifle length, carbine weight buffer but can't find one). BCM FA IonBond Bolt/BCG, and Gunfighter charging handle.
Justin