It is not fair to compare an issue M16/M4 to a National Match rifle... off the shelf or otherwise... they are two very different firearms. My issue M16A1's (yes, I'm that old...) were sloppy, banged up, loose fitting, and certainly a parts mix-master after years of service. Colts are good rifles, but they are also a mechanical device, assembled by humans... so they are not always perfect. When I was in the Army, I never had a Colt... always GM HydroMatics and a single H&R... but they were all made under contract and were interchangeable with the Colt as far as I was concerned. Civilian AR's are something else entirely.