Stop drooling it's not real. Yet.
So I'm thinking about the Tenko determination right, and the issue seems to be ATF on their bullshit. In the interest of getting what I want (a .22 that has mag dumps like a truck dumps dumps like a truck) I keep thinking that a dedicated .22 might be the ticket. 3D printing can get us most of the way there, so how feasible is it to designed an upper receiver which satisfies the following:
A: can only function when attached to a F/A capable MAC-10 lower
B: can run a reasonably common .22LR magazine. 10/22 would be ideal? No reason to add excess bulk with a 15-22 or Ceiner mag
In my mind's eye, it uses the magazine well as an index point (maybe a buffer inserted into the mag well) and the "upper" attaches using the stick fixture, and runs magazines just in front of the pistol grip. There's likely going to be a lot of wasted space but that should make things easier? And if it's going to attach by the stock points and mag well, no reason it can't run a simple trigger bar from the forward trigger and grip back to the actual FCG right?
Help me obi wan MACnobi.