Pretty sure the kits they are referring to are “unfinished or 80% lowers” which become functioning with a trivial amount of drilling and cutting and are essentially sold as raw material instead of a part.

It’s not a trivial amount. I’m in the process of finishing an 80% AR-15 lower. Deep pocket milling with a hand router and crappy endmill just sucks.

The glock 80% market is blowing up with very very easy to finish kits. It can be done with a hand drill and an xacto knife in under a hour.

The shooter in the article probably built a 1911 from an 80% kit and the kits are getting easier to finish. The virginia tech shooter used two pistols I believe.

Just stating that some pistol kits are very easy to finish as opposed to an ar/ak

I’d think a 1911 would require more, given they seem to be so finicky. Maybe that’s next on my project list. Glocks, meh. Never cared for them.

The ATF raided some shop in CA specializing in polymer lowers. Claimed they were too easy to finish, though they still met the 80% standard.

You can buy unfinished lowers ("80% lower receivers") with no serial number, since they are not yet functional lower receivers. It's really easy to buy these, and not too difficult to finish them. Then you have a 100% off the record firearm.

You don’t even need to buy the lower. 3D Printed lowers work just find. In addition you can also just make a mold out of sand. Melt down a bunch of aluminum cans and cast a lower.

This stuff isn’t rocket science.

A cast lower would still require a non-trivial amount of machining to get it within tolerances. Forged lowers are still machined.

I've seen people with no prior experience do it just fine. I feel like people underestimate what average humans are capable of with only meager determination.