Actually, if you look up the definition of "arms", you'll see it to be unrelated to any specific kind of weapon. The fact is, every single American has the right to bear any kind of arms -- though I government currently limits us.
Think about this: Is the number of rounds in a gun going to save you from our tyrannical government using biological and nuclear weapons on its own citizens?
Dont think that can happen? Tinfoil hat time you say? Perhaps so. But honestly, our government is steeped in tyranny now (to support themselves as a noble class) that I put nothing above them.
I want our Constitutional government back. God help us attain that peacefully!