Non-picrate whistles

Non-picrate whistles, made from a mixture of 1 part powdered gallic acid and 3 parts potassium chlorate, are considered to be safer than those which contain picrate. The mixture is charged into a %-inch case, 5/16 inch in internal diameter. The case is loaded on a 1-inch spindle, and the finished whistle has a 1-inch length of empty tube which is necessary for the production of he sound. Whistles of this sort, with charges of a chlorate or perchlorate explosive at their ends, are used in chasers, whizzers, etc., which scoot along the ground while whistling and finally explode with a loud report. 

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