Seeing as how the NRA signed off on a ban of new licensed "fully automatic weapons" in the FOPA of '86, and I can't recall them in my politically aware lifetime

Seeing as how the NRA signed off on a ban of new licensed "fully automatic weapons" in the FOPA of '86, and I can't recall them in my politically aware lifetime challenging the NFA of '34's licensing regime for full auto-weapons, perhaps you might want to study up on this. If by "modern NRA" you mean the post-"assault weapons" ban NRA, extremely notable because it was the first Federal gun control measure they didn't support, you need a better analogy, one I can't think of. We've already given up so much I can't think of any "extreme product" that would fit the bill.