Bob, cheers for clarifying "rifle" vs "gun" for those who aren't familiar with the distinction.
Favour for a favour, I shall distinguish for you "over sensitised" with "an understanding of faintly responsible gun ownership."
"Over sensitised" is a borderline manically paranoid response to a stimuli, for example, thinking that despite all the laws, you need (and are allowed) to pack a firearm into your carry on, that is not only loaded, but also made ready.
"An understanding of faintly responsible gun ownership" means we get that you like guns, we know that guns are simply a tool but we tend to think that giving every yahoo who wants a gun, with limited checks on them and no training, isn't, perhaps, quite the best thing to do.
Anyone, short of a sky marshall I guess, who thinks it's fine and dandy to bring a bloody firearm in their carry on onto a plane, and frankly I couldn't give 2 hoots whether it's loaded or unloaded at this point, is, IMHO a f***ing bellend and deserves being slung in the clink without being told why and left to guess why. Once they figure it out, then they can be released, given some basic bloody training in fireamrs (and Not Being A Bellend 101) and sent on their merry way.