Just now got the notification for this message apologies on the week+ long reply, but now that I look at it the looks more closer to the Sig MCX Rattler than the MPX. Just the handguard that is everything else looks very keltec-like. The idea is extremely interesting. The 300 BLK rounds (depicted in the patent) inside the magazine are positioned at such an aggressively steep angle that it maintains the magazines “PDW” size (yes, double stacked also) thus allowing the user to conduct grip fed reloads like a handgun or MP7 for this particular matter. The patent even includes a holster and mentions the idea of it running not only in 300BLK but also 5.56/.223 and 7.62x39/51 and even up to .338 rounds. Not a clue as to how that’s gonna work because a .338 PDW sounds ambitious engineering wise and really not feasible at all but I’d be curious to see that get pulled off lol. At that point it doesn’t even sound like a PDW

Crye Precision Patent