Some have the allusion that it takes a big factory to build guns. Yet, David Marshall Williams made a semi-automatic rifle while incarcerated in prison. He built it in the prison machine shop.
Basically, it was the one used by hundreds of thousands of soldiers during WWII. In some some ways, it was a better gun for war than those that were designed and built in the big factories.
I have no doubt that a good blacksmith with the proper tools can build rifles or sidearms with nothing more than a little of the right raw materials and a few good tools.
Some might want to consider that when they say we should make guns illegal. At least the ones we have now have serial numbers and can be traced to some degree. If people start making them in basements, we won’t know where they come from, or, for that matter, what country they come from.