Made this at work with kids today. Barrel approx 0.33" OD, 1.25" OD.

https://lh4.googleusercontent.com/-e...609_153812.jpg

I want to have some idea of how much gunpowder I can put in there, and
what is the best way to make some safe projectiles like wads of paper
or some such. I want a modest BOOM and as little destructive power as
possible.

There is a small hole on top for putting in an igniting cord.

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