Serial # CMH******. This thing has A2 upper, with push pin lower, no sear block and regular(not milled) bolt carrier. Upper is black, but different color from lower. Marked match HBAR.

The strange thing is the upper. No bayo lug or flash suppressor.ie.. slick barrel.
Only markings on the barrel are SS and 556. the barrel is black, but might be Stainless.
It has no CMP markings, or twist rate, but has taper pins on the fron sight assembly.

My question: Did Colt make such an animal, or is the upper from someone else? The taper pin assy. looks correct, but I've never seen a barrel with those markings.

Any help appreciated.

I may be wrong but I think the "CMH" serialed rifles were the Competition Match HBAR's. That is, postban heavy barrel with the detachable carry handle.

I'm also thinking the "SS" "5.56" markings were used by Olympic Arms. So I would say someone switched upper receiver assemblies on this rifle.

You are correct on both points.

Thanks, guys. I knew it didn't look right, but I didn't know Olympic used taper pins like Colt.