I guess this could be broken down into 3 scenarios: 1 like in Paris where you are out and about and some one starts running people over, so your only options are a pistol. Do you carry something big that only holds a few rounds like a super redhawk, S&W X frame, desert eagle. Or something that just holds a ton of smaller ammo like one of those real high cap 9mm, 40 or 5.7x28 pistols that holds a box of bullets. 2 you are driving in your car and a truck starts smashing through traffic. Then its reasonable to assume you could have a long gun. Same dilemma AR-15 that holds a ton of ammo or a P90 (if you are willing to go the NFA route) or PS90 that hold a case of ammo or something big that holds less ammo like an M1A or Garand. Or compromise with an AK. 3 How would you defend you house or business from a car or truck ramming attack? The only thing that would limit this would be your budget, immigination, NFA laws. For example I have beach barricades made from scrap metal that I weld additional scrap/spikes to and I can chain or cable them all together. I keep these kind of hidden in the back yard, for now. All of these have happened some where. Even in my little $#!+ hole town an illegal stole a car and used it to ram through the front of my friendly neighborhood gun, hardware, farm supply store to steal their guns and ammo. I guess he forgot he wasn't in mexico anymore. Just a few years ago a tractor trailer went on a rampage on a cali highway, so due to their gun free zone utopia laws people are almost helpless in that situation.