I’m trying to find out some information on it and all I can come up with is CK = Colt / Kaiser Aluminum.
I’d like to find out approximately what year it was manufactured, if it is indeed a Colt, what model it came on, and an estimated value. Any help would be greatly appreciated.
I didn’t see ANY markings on the barrel when the handguards were removed either, but again any help would be appreciated.
Surprised no Colt pros have chimed in on this one…
To me it’s interesting the bayonet lug has been milled off an MG upper.
My Colt M16A2 Commando’s have A1 sights, bayonet lugs, barrel markings, current delta rings and A2 flash hiders…
So I’m going with that it’s not all original Colt, unless it started out a Colt A1 Carbine upper and someone cut the barrel…
That still doesn’t explain the missing bayonet lug.
I have two Colt Commando barrels and we have one at the PD and none of them have bayonet lugs on them. Colt does not install bayonet lugs on current Commando barrels. But I don’t know if they ever did in the past. Plus the current ones are marked “C MP CB” on the top of the barrel, in front of the front sight tower.
The upper in the photo has the Colt proof mark on it. So it did leave the factory with a barrel installed.
Lynn
since the barrel is not marked It could be a 16’’ model 6520/6530 cut down to 11.5’'… some came from the factory without the bayo lug.
Scottryan will know for sure
S,
IIRC there was a MP mark on the right side of the barrel between the two taper pins.
Later,
Robb
As far as I can tell from the info I’ve managed to gather it is a 639 XM177E2. Or a Commando 733, 733A, 734, 734A or 735, at least according to the options listed on Wikipedia. I’ll have to look at the twist rate as that seems to be the only difference between the XM177 and the Commandos. The XM177 did NOT have a case deflector but it was an option on the commando.
If anyone would like to double check, here is the link
en.wikipedia.org/wiki/AR-15_variants
Colt # 639
Model XM177E2
Colt # 733
Model M16A2 Commando
Colt # 733A
Model M16A2 Commando
Colt # 735
Model M16A2 Commando
Now if I could figure out an approximate year of manufacture, I’d be a little happier.
Thank you all for your help.
Thanks for taking a look at it Robb, much appreciated.
My (3) Colt M16A2 Commandos all have bayonet lugs.
Two arrived from Colt on Jan 3rd, 1986…serial numbers are consecutive 80241XX & 80241XX.
I have another that came in a month later, serial number 80244XX.
Why? If the throats not erroded out and it runs, who cares when it was made? 
Blast away!
I also have a similar Colt upper. Although mine has the brass defelector, round FA instead of the tear drop, and no bayo stud. Great upper.
Haha, i definitely plan on shooting it. Year of manufacture is more of curiosity.
So are you going to have Bolt Carriers tomorrow Robb?
I’m pretty sure, if not I’ll give you $100 for the upper! 
I don’t know if I could do that, I think I have about $116 in it if you include the gas tube and pin.
I’d axe that idea.