Actually ammo reloaded at home shoots better than factory ammo this is a known occurance. And guns put together with kits usually shoot better and have less problems than mass produced factory ones.

Guns aren’t really that difficult to make. Hell that Japanese guy shot Shinto Abe with a gun he made himself although bit of a different thing because it used a battery to ignite the gunpowder but still the same idea.

Making guns isn’t hard to do.

3d printed ones are a joke though. You can only use them a few times before they become even more dangerous and unpredictable.