Guns are easy to make if you don’t need them to be highly accurate.
In the civil war, mortars and roadside bombs will be the major weapons, as they are in the Middle East.
Ammo is tougher to make, and simply no longer possible to track.
Not stealing other peoples’ money via government is easy, though.
I’m a pipefitter by trade. Give me the length and diameter of the pipe you be needing. If you order today you get two free caps with every order.