I try to look at these examples from the perspective of the Non-Agression Principle – to come to the conclusion that a specific technology must be kept from the public, it must be shown that that technology, by it’s very nature of existence, infringes on the rights and freedoms of those around it. For example, if we look a nuclear warhead, as you mentioned, it could certainly be argued that it’s private ownership would violate the NAP, as it’s very existence is an indiscriminate threat to the life, and property of any proximal to it. A similar argument could be made for your other example of anthrax. Making a similar argument for an outright ban on the civilian ownership of a fighter-jet is much more difficult to justify, however. I would argue that it would, instead, be more logical to regulate, rather than prohibit, the civilian ownership of a fighter-jet, much in the same manner as the civilian ownership of any other typical aircraft.

It also should be noted that it entirely depends on wording/language. The 2nd Amendment specifically states “[…] the right of the people to keep and bear Arms, shall not be infringed.”. One needs to have a precise definition for “bear”, and “Arms”. Perhaps it could be argued that an individual cannot “bear” a nuclear warhead. Perhaps “Arms” are only those used by the military, or other federal entities. I have no definite answer, but these are the sorts of things that one must consider.