2nd amendment would seem to allow someone who could afford to buy anti-tank or anti-aircraft instruments, for example, to own them.
Of course it doesn’t allow anyone to use them or murder people with them.
When I was a kid (back in the '50s) one could order a 20mm Lahti cannon through the mail and get it delivered to your house. I forget the price, but I know I ordered a nice military surplus rifle and had it delivered to my front door. It was a lot cheaper than the cannon ($23.50 delivered, complete with a bayonet and lots of hunting ammo). Of course, I was only 14, so I had no use for the cannon. But the rifle I hunted with for years. I even took it to school.
These were in the dangerous and Wild West days before the 1968 Gun Control Act, which was passed in the hysterical wake of the second Kennedy assassination.
The same hysterians are at it again. Some things never change.