That statement grossly underestimates the resourcefulness of the average American conservative.
I agree. Bullets can be molded from wheel weights if you have the right molds. Primers are more of a problem. Ditto for powder. Home brew powder isn't likely to be as consistent in performance as the commercial product. When accuracy is paramount, you want all the ammo you're loading from the same can of powder for consistency. The bench rest accuracy fanatics even pay extra for "bench rest" primers that are manufactured for consistency of primers within a given lot as well.