H3 is a pyrotechnic composition which is mostly used as burst charge for small diameter shells. It is friction and shock sensitive, as are most compositions containing chlorates and should not get in contact with either sulfur, sulfides, sulfates or ammonium perchlorate. The name "H3" refers to the traditonal composing of three parts hemp charcoal for every ten parts of potassium chlorate, however this is not the commonly used ratio.
Method Grind the potassium chlorate by itself in a mortar and pestle or coffee grinder until it is a very fine powder. The same needs to be done to the charcoal. Remember both chemicals need to be very fine, like talcum powder and never grind them together. Add 2% of the total composition weight of dextrin and screen the chemicals together by passing the mixture several times through a mesh screen. Once you have done this put the mix into a clip seal bag and close it. Gently roll the bag over itself until the composition is mixed very well. Another method of mixing this composition is the diaper method. Instead of potassium chlorate you can also use sodium chlorate.