It looks slick, so does the LeFrance M16K, but at the end of the day it's pretty hard to beat a modern FF'd bbl., Geissele 3 gun or SSP trigger and a JP FMOS BCG... Though I know that's not what Buffalo is asking, just saying.
I always wondered who at Colt comes up with some of the shit they make, some of it makes zero sense, is over built/engineered or is several years behind the curve.
Okay, all that said, where do I get my upper?
Hey Buffalo, FWIW I found a complete port firing gun on Gunbroker. And there's two kits on there that would make one too, one has the upper and stock the other has the open bolt guts. I'm not sure what the legals are on building an open bolt gun like that in semi but the parts are there. Figured you might be interested.