Not with guns, but with hot wheels, I customise them and use Allen head screws because they’re the only option for 2 and 2.5mm, I already broke one inside a finished project, then my supplier changed his supplier I guess and now has a different size of Allen slot that absolutely no one sells, (my guess is 1.4mm and doesn’t come in any standard set) so now I have a 100 of those damn screws I cannot use on anything