I have not heard of a bronze cannon failing with a standard service load,
the one gun I remember reading about in back in the 1970's was a bronze gun
with a cored bore, it was being used at a college football game I do not remember
the bore size but they used 1 pound of powder and packed it with wet news paper,
the gun did not blow up but the chaplets that supported the core when the gun was
cast were blown out the side of the gun damaging some parked cars.