When in school ( 6th form) we had a Science Society. After school sessions exploring things.
One was an explosives session. Started with adding sodium to water, burning magnesium. Then on to proper explosives. Gunpowder first. Blew a hole in a ceiling tile ( lid on the tin was too tight so a proper bang! Moved on to various other explosives, including a version of napalm. Igniting it was the hurdle but overcome. Nice fireball result! Outdoors not in the lab. Finally a cannon firing 1/4" ball bearings as an example of a practical use of gunpowder. Took it across to the nearby seashore, wedged it in the railway ballast embankment ( LARGE rocks) pointing across the Loughor estuary towards North Gower. Estimated range of 1/4 mile before we backed off for safety. Didn't want to shoot sheep or horses grazing on the salt marsh opposite.
Great fun in those Science Society sessions. Teachers were superb but these days would be frowned on.