Also, I would note wizards seem, on some fundamental level, to be unable to comprehend technology, just as Muggles seem unable to comprehend magic.
Example 1-<PERSON>, a man whose job was to prevent misuse by wizards of items created by muggles, seems, thoughout the books, to be completely unable to understand how such items work--even though he's presumably been dealing with them for years, he can't even give the right names or terms. Examples--the Car in "Chamber of Secrets", the <PERSON>'s living room in "Goblet of Fire", and his lack of understanding of the term for plumbers in (I think) "Order of the Phoenix". Example 2-<PERSON>, in "Order of the Phoenix" was seen examining a dishwasher as if this was entirely new concept--and <PERSON> was (1) smart, and (2) actually interacted with muggles on a regular basis as part of the staff of the Prime Minister. Examples 3 and 4-- In the same scene in "Order of the Phoenix" <PERSON> also was fascinated by the dishwasher, and <PERSON> was seen giggling over a potato peeler--which is about the most self explanatory tool ever. Example 5-<PERSON>,in "Order of the Phonex" tells Mr. 573
<PERSON> he felt he would be completely incapable of driving a car. Example 6--Ron has to use magic to pass his driving test in the epilogue to "Deathly Hallows" despite living with <PERSON> for more than a decade.
Coupled with the face technology didn't work at Hogwarts, and the possibility that this was true in other areas with high magical concentrations--such a wizarding villages--I suspect a wizard with a gun would be more dangerous to himself than to an opponent. This would also apply to eleven year olds raised in the muggle world like <PERSON> (<PERSON>), <PERSON>, and <PERSON>--immersed in the wizarding world, it appears that as they develop as wizards, they lose interest in the muggle world. I think, at 20, <PERSON> would be fully capable of disposing of dark creatures by the truckload as an Auror, but likley baffled by cellphone. It may be that a mind trained to use magic simply cannot understand tech, and vice versa, no matter how intelligent--which, if true, solves the problem neatly, with only a few dangling issues. 194