And you would be wrong...

The "SP" designation tells you it is a 10" barrel. NONE of the 6945/6946 (10.3 inch barrel) SBR's have a bayonet lug. Colt is doing it right. If you can't put a bayonet onit, it doesn't need a bayonet lug.

EDIT for better photos

My Colt 6933 SBR w/ new Colt 6945 upper.


Partial Colt 6945 box label.

In MD?

Was not sure the AAC 18T mount would clear the bayo lug on 6946 upper without modification such as required on Colt 10" M4. It worked.



Colt 10" M4 required slight modification to rear of mount which you can now do with a high quality shim:

Accurized semi over a couple A2s; just fitted with upgrades not yet function/accuracy tested. Will see how they perform with BH MK 262 and 5.56MM 70gr. ammunition. Colt 10" M4 upper being replaced by the 6946 never missed a beat and was surprisingly accurate out to 300yds. I hunted with it where lawful.

I am old school. 1st factory Colt AR-15 select fire was $280 + stamp, 2nd $300, 3rd $320, etc. Just traded up thru the years.

I guess that means we can add Green Mountain to the list of real MK18 barrel manufacturers.

This could blow Augee's mind...

ETA: Colt provides the spec on the barrel manufacturing process, so I'm not exactly sure how Colt decides to award a specific outsource contract, but they do seem to favor GM as of late.

Great, now you've done it.

I can just hear the "just as good" crowd now...

I would still consider a Green Mountain subcontracted barrel to be a Colt barrel. I doubt I could call Green Mountain and ask them for the same barrel they build for Colt and they would sell me one. If you can only get it from Colt, and its Colt's specs and tolerances, and it ships to you from Colt, not from Green Mountain, for all intents and purposes, it's a Colt product.

Don't worry, the just as good crowd will continue to insist that their Green Mountain commercial production barrels are just as good as Colt barrels - "because Green Mountain makes Colt's parts."

~Augee

I really wish that they would come out with a longer railed mono. 7" just isn't long enough for me. I'd take 2 if they were 9-11" long. Had a 6940 and just couldn't get past it. It was an unbelievably accurate Colt. By far the most accurate Colt I ever ran that was a capable of printing MOA or better (got a .62 with 69 SMK) all day long.

I hope Colt starts to follow some of the other high end manufactures cues.

I'm confused. There are pictures of a 6945 on page 2 showing a bayonet lug. What am i missing here?

Why did they mill them off on completet rifles but not complete uppers?

MK 18 and CQBR barrels retain the bayonet lug because the original CQBR project consisted of cut down 14.5" M4A1 barrels.

For whatever reason, Crane didn't bother cutting the bayonet lugs off - Colt was asked to produce the same barrels in a factory configuration. Crane left the bayonet lug - so Colt did as well.

For a while, SAW was offering "SP" (Special Purpose) versions of Colt rifles with 10.0" barrels with shaved bayonet lugs. "CQB" variants tend to refer to those using the CQBR/MK 18 barrel in 10.3" and "usually" have bayonet lugs - however, the 694x series uppers and folding front sight are not govered by any military specification, so sometimes have their bayonet lugs shaved off.

Generally speaking, Colt's policy has been "if it doesn't accept a bayonet then the bayonet lug gets removed" on commercial select fire offerings, however, some late XM177E2s also had bayonet lugs intact - though almost all of them seem to have gone to foreign sales (pictures are seen of them on Filipino XM177E2s as well as UK SAS).

The 10.3" barrel is an oddity because it is not a Colt commercial offering "per se," it was developed by NSWC-Crane, and Colt has only just begun "officially offering" the 10.3" barrel length - because the military ones retain the bayonet lug, some of the commercial ones do as well, but there doesn't seem to be a clear "parameter" yet of how 10.3" barrels are to be set up.

~Augee

Not in the 10.3" barrel, at least not yet.