So how is it reasonable to restrict my right to own a mortar or some other anti-tank weapon if I can afford it? Is it because these weapons would be used in a criminal fashion, say for armed robbery? How is an RPG to be used in a crime that could not be performed by crude bombs or other obtainable explosives such a big advantage? Maybe just to evade arrest? I cannot fathom the reasoning for posession of weapons to be "reasonably" restricted. The USE of these weapons is what can and should be "reasonably" restricted. The very reason for the second amendment is so the people can resist a military force used against them, foreign or domestic. The "reasonable" restriction you support is to limit the people's ability to kick the government's butt.
Well, the second amendment referred to keep and bear arms. "Arms" have never, AFAIK, been interpreted to include mortars, RPG's, etc.
Now, you certainly have the right to interpret "arms" any way you wish. But Congress and the courts have their interpretation, and that's the one that counts.
If enough citizens get together to pressure Congress to include RPG's under "arms" I imagine that it would pass. But it would be a hard sell, and would give the wrong impression of gun owners as a group.