I know guns made before 1898 and replicas firing non commercially made catridge's have little no laws except on machine guns. I know even a felon can own these guns. My question is this, since they aren't considered your typical firearm by federal law, does that mean they may be carried on federal property? My reasoning for asking is we have a mail box at the post office and there's a few shady people in the area at night, which seems to be the only time I have to check it. I'm always holding the keys in one hand and my other hand in pocket while holding a pocket knife. The chances are slim of anything happening, but who knows. And the thought of a local post office was just robbed at night a few weeks ago is always in my mind. I don't want to be in the right place at the wrong time. So, is it legal to have one of those guns on me? I can't find much information. Any help is greatly appreciated.