Right I understand that, but it's still a difficult task to build a reliable and functional semi-automatic weapon from scratch.

No doubt. That's why we bought them at gun shows. While my buddy was machining himself a 9mm smoothbore, we were passing on Finnish anti-tank cannons for $1500.

My uncle didn't like guns in the house, so my cousin experimented. My buddy Matt's parents didn't like guns in the house, so Matt experimented. Meanwhile, I could go plinkin' any time I wanted with 3 SKS, an AK-47, 2 AR-15s, an M1 garand, an M1 springfield, an AR-7, a .357, a .45 and my personal favorite, the 12-gage/30.30 over-under "bear gun."

The thing that has changed the most since then is the cost of ammo. I used to get Chinese steel-core for 2 cents a round - then that asshole who makes the Thomson Contender decided 7.62x39 was a great pistol caliber so suddenly it became import-banned. Then all the crazy 'wingers decided Obama was going to take their guns so the ammo industry started gouging. Frickin' 5.56 - the Prepper round of choice - is now over a buck a bullet. Trust me, I know - I bought the limit (10 boxes of 20) for a buddy at Stockpile Defense.

The 3d printer thing is a red herring, same as the "glock panic" back in the '80s.