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Smokeless powder does not leave the thick, heavy fouling of hygroscopic material associated with black powder that causes rusting of the barrel (though some primer compounds can leave hygroscopic salts that have a similar effect; non-corrosive primer compounds were introduced in the 1920s). [4]: 21 )
This test is performed under normal conditions at 21 °C (70 °F), but also by simulating cold polar −54 °C (−65 °F) or hot desert 52 °C (126 °F) conditions using special cooling equipment and ovens to cool or heat the ammunition under test to the appropriate levels of humidity and temperatures required.
Number 4831 was used to load navy anti-aircraft machine gun ammunition, and number 4895 was used to load United States service rifle ammunition. As these propellants became military surplus after the war, large quantities of different batches were blended together to make products with uniform average performance for sale to civilians.
Black powder substitutes are measured by volumetric measurement techniques, not in grains on a scale, due to the difference in density compared to black powder. For example, to measure a "60 grain equivalent" of black powder substitute suitable for use in a muzzleloader rifle, one uses a volumetric measure that produces a volume of black powder ...
A corrosive material is a liquid or solid that causes full thickness destruction of human skin at the site of contact within a specified period of time. A liquid that has a severe corrosion rate on steel or aluminum based on the criteria in 49CFR 173.137(c)(2) is also a corrosive material .
They commonly swab the web of the non-firing hand to look for gunshot residue if they are suspected to have discharged a firearm themselves or were in close contact with one at the time of discharge. Hair and clothing also accumulate GSR; typically a double-sided adhesive is used to sample areas that may have been exposed to such residue.
The salt spray test (or salt fog test) is a standardized and popular corrosion test method, used to check corrosion resistance of materials and surface coatings.Usually, the materials to be tested are metallic (although stone, ceramics, and polymers may also be tested) and finished with a surface coating which is intended to provide a degree of corrosion protection to the underlying metal.
Mercury fulminate has the distinct advantage over potassium chlorate of being non-corrosive, but it is known to weaken with time, by decomposing into its constituent elements. The reduced mercury which results forms amalgams with cartridge brass, weakening it, as well.