But Miller is a precedent that supports our position on what types of weapons are protected by the second.
However, Miller is almost a non-precedent because the lower courts immediately twisted it beyond recognition and the Supreme Court let them get away with it for nearly 70 years. Depending on what circuit you reside in, Miller can mean anything from a pro gun to a completely anti-gun precedent, even though the actual holding had nothing at all to do with the substance of the right enjoyed by individuals. Without guidance, the circuits have made up their own rules, attempting to apply Miller to places it never went. Unlike with other subject matter, the Supreme Court has long declined to step in and settle the split.
We are still waiting for a ruling on who is protected by the second amendment. Individual citizens? Government officials? Soldiers? Illegal aliens? Former felons? Former misdeameanants? This hasnt been touched yet, except in dicta. The dicta suggests at least a strong individual right, but unfortunately is not binding.
We are also still waiting for the supreme court to start applying the Miller test to actual weapons so we can clarify the reasoning and apply it to other guns. Clearly an M16 is a suitable weapon under Miller. But what about a rocket laucher? A mortar? A tank? An aircraft carrier? A nuclear missile? At some point, an individually owned weapon starts to usurp the sovreignity of the US without conferring any self defense or common defense benefits. While a portable mortar might clearly be a useful tool in a civil unrest or invasion situation, a nuke or a carrier has little use beyond attacking distant foreign targets. Etc.