ok, so the plan is to buy a short barreled ar15 lower assembly on gunbroker, then buy a ar pistol and obviously put the little upper on the sbr lower. my question is, what can I do with the pistol lower. Is there a way that I could put a stock on it and a 16 in barrel upper and call it a rifle with a pistol Receiver or is that not legal? I know I can buy the pistol upper separately but it looks like you get a better deal when you buy it all together (the pistol anyway)