ABOUT COLT 6920 UPPER RECEIVER

 Truthfully, I would not shoot 1.  Time to maneuver on to a whole new rifle.  Get an LMT or HK if you prefer armed service design pistons.    Colt has little interest in assisting you out.  They deserted that job just before their past bankruptcy.Quoted: About the ALG/Geissele entrance, They are getting an brilliant Black Friday sale on rails