Appreciate the lead! Helps a lot.Spoke to my son, who is a gun nut for AR's. He said Daniel Defense is your best option, since all the internals have been modified.
With Colt, to get the fine internals, cost alot of extra $. The Daniel Defense rifles run between $1500-$4000.
A good one is a DDM4 V1. It shoots a .556 or a DDM4 V7 PRO. Then you add the sights you want.