At face value, "...the right of the people to keep and bear arms shall not be infringed" would mean the federal government does not have the power to decide what weaponry could be retained among the people to ensure the security of a free state.

At some point it reduces to what level of weaponry can an individual expect to responsibly secure and maintain? A run of the mill gun safe could feasibly secure anything up to a machine gun or shoulder fired rocket/missile, but above that you're looking at either extreme wealth or group organization to say, keep and protect a nuke, or hangar and protect a weaponized UAV.

I would argue that the limit isn't based on how potent the weapon is, but at what point the cost and risk of losing control of the weapon outweighs the benefit it provides to maintaining a free state