>Design completely new upper, lower, gas tube, and gas key for an AR
>mag release and mag are replaced by a captive magazine that can slide up and down a certain distance with pressure-sensitive locking at the top and bottom
>upper has a section cut out extending the opening of the ejection port to the top of the receiver
>gas key and contact point with gas tube are moved closer to the hole the tube protrudes from
>magazine down -- BCG can move and chamber a round
>magazine up -- BCG is locked to the rear and new rounds can be thumbed into the top of the mag
>brace mag in left hand and use stripper clip with right
It's novel but it's legal right? Just an idea that came to mind, I know it's not more efficient than a maglock and special RTP