Method and article of manufacture of a pyrotechnic device

A pyrotechnic device having maximal audible effect upon detonation comprising:

• a frangible tubular casing, 1-13/4 inches in length by 1/2 to 5/8 inches inside diameter;
• an explosive charge within said casing, said charge being no greater than 2 grains;
• a disc within said casing between said charge one open end with said disc and sealant closing off said one open end of said casing and at least a sealant closing off the other end of said casing, said sealants being axially spaced from each other to define a hollow cavity containing said explosive charge whose volume is substantially larger than the volume occupied by the mass of explosive charge with said cavity extending approximately one-third the length of said casing;
• said casing being of 0.015 to 0.040 inches in thickness and said disc having a thickness of from 0.010 to 0.125 inches;
• a fuse secured within said casing in communication with the explosive;
• and
• wherein each of said sealants is in contact with said casing on opposite sides of said explosive charge and constituting a longitudinally extending solid fillet with the periphery of the fillet contacting the interior of the frangible tubular casing over 15% to 20% of the longitudinal interior depth of the casing;
• wherein the resistance of the casing and the resistance of the sealants is such as to provided a balanced inertial resistance to insure bursting of the casing upon detonation of the explosive charge.