I'm not to sure about MO laws... it's a bit more strict here in AR I do think. It would be something I'd look up or ask a real legal rep.
I know that AR , OK, TX, NM, and MS require the fire-arms of any sort to be cased, locked ,breached, or un-usuable or out of reach when traveling.
I don't see LE in any place making an on the spot distinction between airsoft and real steel. Possibly if they already know what airsoft is... , but most don't, or wouldn't take the time to look into it anyways.
I think it's just better to not give any reason for any bad publicity, or defiance of any law ( even if it's only a perceived defiance , and it isn't actually "wrong" ) to further give congress/fire-arm haters any more excuses to bust down our fun little hobby. By the looks of things, you have media and governmental and legal reps just looking for any excuse to jump on the hobby in any negative light they can.
Just look at the article posted above.
True, the boys should not have been out in public with airsoft guns. They should have complied with the LE.
However, I don't see them as completely at fault.
The LE could have done a number of things ... pepper spray, shock-taser, and other non-lethal methods come to mind.
Of course, I wasn't there in the situation to know for sure..., but it's really hard to imagine it was 100% all the kid's fault.
But if you look at the way it's written... it's rather pointing the finger at the kids as being the culprits. It points out airsoft guns as the blaming factor.
" Another Kid shot because of Airsoft Guns " is how it reads.
not...
" Another Kid shot by officer in misunderstanding."