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I believe you need fuming nitric acid to manufacture smokeless powder, which you can't pick up at any hardware store and I believe is helpfully on the list of drug precursors, so trying to buy it gets you on (yet another) list.

You can make it with sulfuric acid and a nitrate salt. It is possible to get nitrates from the air with a spark gap and water. Wikipedia and YouTube have the details on how to not kill yourself doing it if you possess an IQ above room temperature.