Recoil posted this on Facebook and Instagram, they have been hanging out at KAC the last few days so maybe they found it in some old literature, the page formatting looks like something from collector's  grade though.

Nevermind it's something Recoil made up.

The A2 lower receiver gives it away...

Years ago, Olympic Arms made something very similar, but IIRC it had a free float hand guard. They called it a K23. Maybe it's a misprint in the photo. Definitely doesn't look like something Colt put together.

The photo is just something Recoil doctored up as well.

M2C made something very close called the M16X.  I seem to remember Kevin B. mentioning many years ago that the Canadian Forces evaluated the M16X and the slightly longer M16C for their PDW requirement.   (How long ago?  Well, Kevin was still a member of the Canadian Army back then.)

I don’t know about them evaluating M2 Corp.  It’s possible I suppose.  There was a photo kicking around of a Diemaco prototype.  It had a cut down fiberlite stock just like Recoil did (think UCIW) and an extremely short barrel. IIRC it was something like 4”.  They cut down a FSB and only retained the rear portion for the gas tube.  Handguards were extremely crude cut downs, similar to Recoil but uglier.  I think it may have been the brainchild of a guy named Crocker who was a CF wpns tech at the time.  He did go on to work for Colt Canada after he left the forces but I’ve heard that he fell victim to the Colt bankruptcy and was let go.

Someone on here also had a cool looking cut down upper that still used CAR handguards but the handguard cap was in front the FSB.  Barrel was 8” or something like that.  Had a custom gas tube.  Guy had a lot of expensive retro toys, including an M134.

While they may not have been Colt developments there have been some cool retro PDW style guns, like the stuff that came from Tim LaFrance.

A retro PDW in .300 blackout would be pretty cool.

ETA:  Found the Diemaco: https://www.ar15.com/forums/ar-15/-ARCHIVED-THREAD-US-Army-Mulls-Requirement-for-Personal-Defence-Weapon/12-318260/&page=2. He does mention Canada looking at M2 Corp.

I must have it bad. Someone doctors a photo and now I have to build one...