I don't know what crackpipe you're getting your ideas from. Yes you can. Read into the "Castle Doctrine", espically the new additions to it passed with the "No-Retreat law." You're on my property at my house, its open season on your ass, bitch. Seriously, if someone is on your property at your house now, doesn't matter WHAT they're packing, if you're threatened and they're uninvited and not living there then you reserve the right to dispatch them.
Edit: By that, I DON'T mean you can shoot Johnny jogging by your house or Mr. Sanders walking his dog in your yard. Also, I don't mean you can shoot someone on the street for stealing your wallet. I mean you can shoot some shady mother fucker in the middle of the night hovering around your house and your property at your house because you don't know if he's there just for your property or for you, and by the Castle Doctrine he is assumed to be there for you as well.
And thanks chet, I love you too. I like how nobody here understands what a hyperbole is.
Edit Edit: Because you pissed me off so much, I did some legwork for you.
http://writ.news.findlaw.com/sebok/20050502.html - Castle Doctrine changes with the Stand Your Ground(No Retreat) Law
"Second, the new Florida law expands the definition of "castle" to include vehicles -- such as cars and boats. This expansion the castle doctrine was clearly intended to address carjacking. "