Yes it must be... Gunners always celebrate St. Barbara´s day.
They are just a lot of exuberant noise makers.
To help you Pippin here is the legend - damn artillerymen light the fuse and pray.
Saint Barbara lived and died about the year 300 A.D. She was venerated as early as the seventh century. The legend of the lightning bolt which struck down her persecutor caused her to be regarded as the patron saint in time of danger from thunderstorms, fires and sudden death.
When gunpowder made its appearance in the Western world, Saint Barbara was invoked for aid against accidents resulting from explosions--since some of the earlier artillery pieces often blew up instead of firing their projectile, Saint Barbara became the patroness of the artillerymen
Thanks :o)
That, and the propellant smoke has some odd addictive quality to it.