I don't look down them out of habit from being around them in a operational enviroment, with the right front strut precharge a F-18 cannon points right at my head. An AH-1W manages to point at everyone. I have read of a few accidents where the gun was electrically actuated for the purpose of gun maintenance only come to find out it had a few rounds left in the chain. Most recent I remember was with a CIWS, no one was injured, but...
So, If I see folks working on the guns, uploading, or downloading I steer clear. And yes, some aircraft do normally carry a full drum for weight and balance. It will be training rounds, but that only means an inert projectile which is fully capable of firing. At an airshow I would consider your risk to be less than minimal.
Other fun with ordies. A popular disarm technique is to not read the checklist, not have a clue what you are doing, but apply ground power and cycle the "jettison all" switch. Amazingly enough, it works
. This has been done. More common is the drop tank shuffle where a couple of strong fellows get together to lift off an Empty drop tank from a wing station this is usually preceded by someone saying "yeah it's empty" from relying on how the tank sounds when tapped with a wrench. The releases are actuated and two ordies find themselves with lifelong severe back injuries because they tried to hold up a tank half-full of fuel.
Then there is always the F/A-18 Sidewinder AD where a Sidewinder missile goes merrily skipping down the flight deck after popping free of a F-18 wingtip rail on carrier arrestment. Always gets your attention.
I've gone to claim some empty ammo cans only to open one up to find some spare electric primed HE 20mm rolling around loose
How about I go away while you guys throw that overboard M'kay? I don't want to be there.
Then there is always that one about the Zuni rocket. Oops.