I now have in my possession a mk12 mod 0 that I'm trying to identify.  It came from a contractor buddy that I served with back in the day who also did some work for Crane during the development days of the mk12.  Sadly he's no longer with us so I can't ask him questions about what was in his gun safe which is now in my gun safe.  This rifle was served with but that doesn't mean anything in terms of knowing the origination of all the parts.  I've identified all the upper parts (which are spot on with early Mod 0's) with exception of the upper receiver and a few extra what I believe to be douglas mk12 barrels.  All it has is the "split A" anchor harvey marking on it and nothing else.  Based off this sight (http://www.biggerhammer.net/ar15/uppers/) I was able to identify it to matching the Colt small hole but there are ZERO colt markings on it and it has the M16 sear relief on it but this still doesn't tell me much.

Obviously Anchor Harvey was used a lot by many mfg's.  So here's my question.  Does anyone have an original upper from Crane on their MK12 or know exactly how to identify one?  Given the history my buddy had with Crane, I want to think it's an original but I can't prove it in any way.  Trying to figure out how to identify Douglas MK12 barrels as well.  My google foo is not very strong lately so figured I'd ask here first!

Thanks in advance for any insight.

MK12 THREAD

Roger.  Didn't know about that thread.  Still new here.  Thanks for sharing.

There was 12 total.
But yes, they were put into the civvie market with a letter of authenticity for each of them. Not sure if they were rebuilt, as they were sent out with their "original" battle worn rattle can jobs.

I wish I had some definitive answers for you OP, I'm unfortunately not as well versed in the Mk12 game as some, specifically about the issued stuff. It's possible that you have had a message or two from someone in the thread after your post in there. There's a couple people in there that will surely be able to help you out, especially so after providing some pictures.

Heres my take...based on my knowledge, issued Mk12 uppers bore the Colt, Colt Canada (diemaco), or, rare occasion, Armalite markings. The Anchor Harvey, afaik, were exclusive to Colt Canada

Attached File

(^ Surplus/issued take offs - Diemaco)

The other bits on the upper you have acquired will also help in ID'ing it..at least, help in figuring out a timeframe of which it was assembled. - as you say you've already done.

ETA: took me awhile to find, but here are markings from a contract barrel. This was a Mod 1 take off, If I had to guess...markings would be pretty near the same for the earlier 0's
Attached File


Mod 1 barrels still had flats milled into the barrel for the set screw fsb used on the SPR/0
Attached File


Issued barrels didn't have much to them, just the manuf. date, "Rev 3", and "PMP" near the extension. Curious to know what you are in possession of though. I sent you email, hit me back with some photos if you could

One of the 12 issued uppers and its letter of authenticity.
Attached File

Without a letter it's hard to prove.

Mine was built in 2003 and has the anchor Harvey colt upper, KAC handguard and Douglas SPR barrel.

Think mine was a MSTN build as I bought it from Raptor22.