friends, there is more than one way to skin a cat. and, more than one way to build an ar-15 lower, and avoid the gd gubment being in your damned back pocket.
the following suggests an alternate route to what i am after.
this is way cool. this method, coupled w/ aluminum adhesives, should build an absolutely hell for stout lower, out of aluminum, totally without the need for a cnc controlled milling machine. i cannot vouch for the fit, nor for the placement of holes and such, but, the concept is absolutely impeccable. go ahead, take a "peck" with it, be my guess: i don't think you can.
do i like the design? in my desk, i have a print out of the plans. does that answer my question?
john jay @ 09.14.2015
http://www.guns.com/wp-content/uploads/2013/12/screw-together-lower.jpg very nice, very elegant. indeed.