The high cap genie is 90% out of the bottle:
I mentioned 3D printed lowers in my first post, and how they're coming soon. Magazines appear to be here, now. Let the pols ban all they want, anyone can now manufacture their own bodies.
1) Purchase 3D printer
2) Obtain model file for 30 round AR magazine
3) 3D "print" the model file
4) Assemble with non-regulated follower, spring and floorplate
5) Use in AR
Durability issues are all that remain.
http://defensedistributed.com/