cordite, apropellant of the double-base type, so called because of its customary but not universal cordlike shape. It was invented by British chemistsSir James Dewar andSir Frederick Augustus Abel in 1889 and later saw use as the standardexplosive of theBritish Army.

Double-base propellants generally containnitrocellulose (guncotton), a liquid organicnitrate (e.g.,nitroglycerin) having the property of gelatinizing nitrocellulose, and a stabilizer. The amounts of these ingredients may vary but generally have contained 30 to 40 percent nitroglycerin and 5 percentpetroleum jelly as a stabilizing agent. Cordite is soluble inacetone, which is used incolloiding the mixture.

The original cordite (Cordite Mark I), as manufactured at the royalgunpowder factory at Waltham Abbey,England, in 1890, was composed of 37 parts of guncotton, 57.5 parts of nitroglycerin, and 5 parts of mineral jelly together with 0.5 percent of acetone. Because of its large content of nitroglycerin, this cordite had a high temperature of explosion and produced considerable erosion ofbig guns.

A modifiedcomposition, Cordite M.D., which was introduced in 1901, contained 64 parts of guncotton, 30.2 parts of nitroglycerin, and 5 parts of petrolatum with about 0.8 percent acetone. Cordite M.D. proved to be a very stable composition with long storage life. The nitrocellulose had anitrogen content of 13.1 percent.

Modified corditecompositions containing other organic nitrates, replacing the nitroglycerin, were introduced duringWorld War II. Such nitrates include dinitrotoluene, nitronaphthalene, nitroguanidine, and diethylene glycol dinitrate (DEGDN). The use of these nitrates significantly lowered the burning temperature, which resulted in reducedgun erosion, permitting the firing of many more rounds from a gun barrel.