Personally I think it's fine (but still stupid) to own a handgun or shotgun or something like that for self defense, but anything military grade or more powerful than that should be illegal.
Military grade is a derivative of Civilian grade. Always has been and will always stem from the basics. The military uses handguns that are manufactured specifically for its troops, however operates the same and is even of the same power as its civilian counterpart.
What really irks me about people who try to argue guns is they set up these "categories" and "walls" trying to draw a line between guns and what makes them different. That area is so grey that even if there was a ban on lets say "military grade" weapons, their civilian counterpart with the exact same function will eventually be targeted also because someone got scared of its "incredible firepower" much the the "military grade" weapons.
The restriction on automatic
firing modes being installed into these weapons however has a lot more sense behind it. I'm glad that its pretty difficult right now to get your hands on one of these. I feel that our nations sense of responsibility in each individual has declined to a degree. In turn this has made us more paranoid in our decisions and on things of dangerous capability that can be obtained. There's much more to this as well that i'd love to add just so i can make a point that its not JUST mentality and maturity that i'm worried about. However i do not have the time as of now.