I'm a little worried by this - mostly when I see points like this popping up, there's a fairly high hit rate of someone planning to use them against people, a little like a version of paintball.
However, on the off chance that's not the case, I suggest the crude solution of filling a balloon with flour. If it's fast enough, and the target is hard enough, then it should create a nice cloud of smoke on impact.
Just DON'T use them against any person.
jrrdw wrote:Explosive device: Any device that has the capability to release large amounts of stored energy rapidly.
I know this isn't a rules discussion thread, but that's a very ambigous point.
A regular spudgun tends to release hundreds of joules in a dozen milliseconds or so.
A car engine can chuck out hundreds of thousands of joules in a second.
Both fit that loose description to a T, but obviously neither of those is against forum rules.