I was at Keith’s machine shop and saw this oddity. It is an AR-15 upper receiver with picatinny rails built into the sides. Both sides.

Keith is borrowing it to take measurements off it but does not know who makes it. I was unable to find anything online about this upper receiver. I am curious what the maker was thinking when they made this. I can only see two logical explanations other than mall ninja status of adding accessories for the sake of adding accessories.

Building an AR without a handguard. This way you can still attach accessories like flashlights. Adding a mini red dot sight like in 3Gun

However with the lack of a brass deflector, I am not sure if the ejected brass would hit the red dot if it was mounted on the right hand side for a right handed shooter.

But if that was the purpose, then why is there a small single slot right in front of the ejection port?

Have any of our readers seen an upper like this? Any ideas as to who makes it?

Edit: Thanks to our reader, Zed, he identified this as a DPMS upper receiver part number FTT-3R.