Andy Cross
New member
Can anyone confirm this information. It was given to me by a chemical engineer who was not a shooter. He worked in quality control in an explosives plant and is now eighty years of age. The story he gave me goes that the number on the canister of powder is derived from two pieces of information. Those being the burning rate and specific gravity ie loading density of the powder.
The burning rate is found by determining how long it takes for one gram of the powder to burn away from a pre ignition temperature of twenty five degrees C at sea level. Time measured in milliseconds. The SG is found by determining how much distilled water at twenty five degrees C it displaces which is calculated in cubic millilitres.
The two measurements have a constant applied to them which results in the number on the canister. Because commonwealth countries use a constant based on the British naval gun standard the same powder will have a different number on the canister when the constant used in Europe which is metric based is applied and be different again when the US constant is applied. To avoid confusion with some numbers finishing up similar, even though the powders may be quite different, a name is often given to the powder instead.
Andy.
The burning rate is found by determining how long it takes for one gram of the powder to burn away from a pre ignition temperature of twenty five degrees C at sea level. Time measured in milliseconds. The SG is found by determining how much distilled water at twenty five degrees C it displaces which is calculated in cubic millilitres.
The two measurements have a constant applied to them which results in the number on the canister. Because commonwealth countries use a constant based on the British naval gun standard the same powder will have a different number on the canister when the constant used in Europe which is metric based is applied and be different again when the US constant is applied. To avoid confusion with some numbers finishing up similar, even though the powders may be quite different, a name is often given to the powder instead.
Andy.