My most recently built one. It's a James River Armory receiver and bolt, Sadlak NM spring guide, XM25 modifications to the gas cylinder, LRB brake, Sadlak Airborne scope mount with a Vortex Viper 1-4 scope. The bulk of the rest is USGI... all sitting in a NOS E2 stock (needs a few more coats of tung oil).