A custom lower with proprietary mags for more COAL in a .223 based cartridge would sell < 500 units. Worldwide. Ever.
Lots of guys will talk about how great an idea it is and how they'll "definitely get one" and when they hit the market those same people will look at their stack of $8 PMags and their bolt gun that's already set up for proper COAL and never actually buy the new wonder-lower.
BS can proclaim the world full of idiots who won't take a hint, but that won't change the fact that a proprietary lower just wouldn't sell.
