Yeah, "nearly as good as high-end manufacturers" for the first few dozen rounds, until the lower-quality metal with inferior hardening methods wears down and it becomes "paltik" and either jams, becomes very inaccurate, or actually breaks apart.

Still, this is why schemes to rid the world of guns by confiscating them all would never work. Do you see them making single-action revolvers and bolt-action rifles? No, they're making simpler, easier to manufacture full automatics.

The real magic is in making the smokeless powder and primers to power the guns.

Yea,the Dutch Resistance during WW2 made submachine guns in a bicyle repair shop.Hell you can order the plans for a simple 9mm submachine gun,and build it using plumbing supplies and hand tools.