The second amendment needs.. to be amended in all honesty. The initial law of the 2nd amendment was not written in anticipation of weapons of the future but solely for the "protection" against unlawful government. Considering its basis is set from a "foreign" governing, being Britain over NewFoundland (US), they wanted to protect themselves in case of another ruled them and taxed them too high etc. which isn't going to happen.
Times have changed. There are different weapons that cause higher capacity of damage to what the 2nd amendment was initially targeting. There are laws, technology where government can't literary drag you out on the street and execute you right there for not paying tax. Police have evolved from back then and so should a 200 year old law that was for flintlock and not gas powered assault rifles.
Personal defence weapons (not to be confused with actual PDWs) should be available to lawful, licenced people. Shotguns and pistols of a certain calibre. Want to have a AR-15 or other weapon? Get a separate more higher background tested licence where you can use it at ranges or any legal established area and store it where it's tracked in house.
If I were a nuclear physicist and wanted to experiment to harness powers of nuclear fission, which required me to have enriched uranium. Which on the other hand, I could make a nuke out of. Just because terrorists do. I'm sane and should be trusted to use such materials but are not allowed.
Same goes for an AC-130. lol