Yep, if you live in Afghanistan or somewhere. But do you seriously mean that the average person in a western democracy needs to do that?
I'm not one to judge the needs of others as you do, but I'd say, yes.
I predict that you're going to go on about how improbable the need for a fully automatic weapon might be used by "the average person in a western democracy", and before you start down that path, I'd point out the nature of insurance. I'll give you a personal example where you would not object (I would hope) to my possesion of an item even though, according to your paradigm, I don't need it.
A fire extingusher in my car, and in my home.
According to you, I should be forcibly prohibited from possessing one because I don't need one. I don't need one, because neither my house, or my car are on fire right now; neither my house or my car have ever been on fire; and the likelihood that they will be on fire in the future is as low as it has been in the past, thus very unlikely.
Also, I have no duty to anyone but myself to put out a fire, thus I cannot need a fire extinguisher; and I am not trained in fire-fighting, and therefore cannot need a fire extinguisher. Besides, there's a perfectly good fire department close by, who have a duty to put out fires, and thus are the only folks who need fire extinguishers; and they are highly trained in fire-fighting, so they surely must need fire extinguishers.
According to your argument from "need" my fire extinguishers should be forcibly (if neccessary) confiscated, and I should be declared a criminal for possessing a fire extinguisher (unless it's "registered" and I'm "licensed" to protect my life and property from fire), and arrested for my patently "criminal" activity.
The point is, despite "need" being a valid criterion to have something, an individual's lack of "need" of something is not sufficent criteria to prohibit and/or criminalize possesion of that thing--whatever that thing might be. Your fatuosly limited notions of "need" just make the alredy weak argument from need rediculously weak.