Nedd to ID an SBR 11.5" Complete Upper

AR/M4 AR Technical Discussion
1

I currently have an 11.5 in SBR upper I need to identify here are the identifiers…

  1. M4 Style T-marked flat top upper reciever

  2. Finish and entire upper looks like a clone of my Colt 11.5 Commando’s Upper

  3. 11.5 in pencil barrel just like Commando

  4. F-marked FSB

  5. Standard A2 flash hider

  6. FSB has bayonet lug sheared off like Colt Commando

  7. Barrel stamped: CMP 5.56 CB

  8. Upper reciever has two stampings over forward assist: #1 - looks like a key hole and #2 is an unfinished triangle with the ending leg shaped like an arrowhead

  9. Same proof marks were also on the carry handle

  10. BCG is a full auto and identical to my Colt except where the “C” is on the Colt it has the Unfinished Triangle with the final leg ending in an arrowhead

  11. Bolt is also shot peened: “MPD” nearest the lugs and below it also shot peened is “J4070”

Any help would be greatly appreciated…thank you!

2

You barrel appears to be a Colt. Not sure about everything else…

3

I have been wondering if it is a Colt Canada/Diemaco Commando Upper Group. It was advertised as a Colt Commando Upper NIB. Local PD had quite a few Commando’s and 6933’s. Lowers went to one dealer and the uppers another. I got a NIB upper. It looks identical to my Colt but other than the barrel which is the only Colt marked part, I don’t know. I know the fella didn’t screw me and I don’t doubt the make, however I would like to know if it is a CC/Diemaco gun. It is an exact clone of my city issued RO933.

4

Colt used to put proof marks on the upper just forward of the ejection port.

But I think it’s been a few years since they’ve done that.

I know one was a small triangle with a mark inside it.

5

Sounds like a real Colt upper to me.

6

Barrel is definitely Colt.

Bolt is Diemaco. MPD = Mag particle inspected/Proofed/Diemaco.

The keyhole and other markings are forge marks (Keyhole = Cerro Metal forge marking), and those are common on Colt and Diemaco guns.

The “triangle” is likely a stylized D for Diemaco, but hard to say for sure without pics.

You’ve got a good quality upper.

7

Well, I could use some help trying to ID these. It has been suggested they are bushmasters. FSBs are not F marked.

The top one is T marked. On the FSB, there appears to be a BOM to the left of of gas tube pin, possibly a 1V before it.

The bottom one is not T marked.

Both have different barrel profiles. They came from a military unit about 2 years ago.

8

Found out on another forum from a good Canadian buddy of mine that it is in fact a NIB Diemaco Commando Upper. The “D” is shaped like this…

9

Thanks for all the info guys. I know quite a bit about these guns but don’t know everythng for sure and couldn’t have done it without yall.