This would be re-issued as the R6601 Match Hbar. Commonly known as a blue label. Less the bayonet lug. Serial would have the prefix MHxxxxxxx. They are pre ban and very nice shooters. Interesting bit of trivia, the first issue Delta Match Hbar had serials that started SP. The second issue started MH. My R6601 is in the top 3 of my favorite ARs. It's also a slab side. Go figure.I have a Colt AR-15 A2 HBAR Sporter Model R6600 Green Label I bought new in the late 1980's.
It's in the Serial# SP2350xx range.
Has the A2 Upper with heavy barrel, bayonet lug, and the lower with the smooth slabside area with no protection around the magazine release.
The day after I bought it, Colt announced they would no longer sell AR15's to civilians.
It's a pretty accurate rifle right out of the box.
I haven't fired it in many years, as I've bought and built several other AR15 type rifles since and just shot those instead to keep this one nice.
Has about 500-1000 rounds through it.