Ummm, you know the 18th has to do with the prohibition of Alcohol which was made illegal to sell and transport in the 1920s, not guns right?
Not that it worked very well, people who wanted Alcohol found a way to make it and sell it and deliver it.
The prohibition of Alcohol led to the creation of Nascar, Souped up cars to transport illegal alcohol or Moonshine and escape and outrun the Police... The movie Smokey and the Bandit was about this.
As far as "well regulated"...
(as a Liberal Democrat, who owns guns and can own anything legally because of my squeaky clean record)
I think background checks & closing gun show parking lot sale loopholes is a good idea, & incendiary explosive devices shouldn't be allowed to be sold to just anybody who doesn't have a legitimate reason to be messing with light arms ordinance, anti-tank, anti-aircraft missiles, (Military Contractor / Manufacturer / Film Production/ Museum)
It's certainly not spelled out in the Constitution that you can own Cannons from the 1700s or hand grenades & rocket launchers, which didn't exist back then, but it also doesn't say you only have the right to defend yourself with a Musket and Sword, while every couple of years "The Government" keeps benefitting from creating more and more sophisticated future technologically advanced weapons.
The idea and message of the 2nd Amendment when it was written being that "The Government" and "We The People" should be on equal standing.
For the People to be able to defend themselves from a "Tyrannical Government" they had to be able to use the same arms that the Government had.
But now 200 years later, everybody who wrote it is dead, and we have created every 30 years, more and more advanced weaponry with changing times, and also enacted laws to prevent the average Joe from owning these newer and more advanced weapons every time that there was a terrible Incident around the country involving one of these newer weapons.
The famous John Dillinger in the 1930s, had Thompson Machine guns running wild in Chicago with the 1st early automobiles, and led to the 1934 NFA, Taxing all new Machine Guns made and requiring registration of the weapons to the owners, in 1986 After Reagan was shot & almost Killed, the Machine Gun Ban, making it illegal to keep producing New Machine Guns (BAR, UZI, Mac-10, AK-47, AR15/M16, Minigun, etc) for sale and Public consumption, Only for Law Enforcement and Military use since 1986 all the way to today.