That is the 80% receiver that someone affiliated with JPFO was doing. If I recall correctly, they got raided by ATF for "illegally" building firearms.
I'm certain that it is still in the courts, and I frankly think that the case will be found to have no merit.
But ATF DID go after them.
What I don't get is how no one bats an eye at AK build parties, but they went after this. I think the question was whether they were truly 80% of if 90% or so of the work was already done.
If I recall correctly, Shotgun News did an article on them a year or so ago.
-- John
