Same aspect as saying, any car/vehicle over 400 horsepower should be illegal. Unless you're Michael Schumacher or Mario Andretti, you can't have any vehicle over 400 horsepower.
The 2nd Amendment states, it is our RIGHT to Bear Arms. It's not a luxury, it is a given Right as an American. Banning firearms infringes upon that Right. As an owner of a few, gas operated, magazine fed, semi automatic rifles, this does infringe on my Right.