Gun propellant grains

Gun Propellents. Although the stresses on individual gun propellant grains are less severe because of the small size, these propellants must withstand much higher weapon pressures and accelerations. Formulation options are usually more limited for gun propellants than for rocket propellants because the products of combustion must not foul or corrode a gun, should have a low flame temperature, and should exhibit minimum flash and smoke characteristics. Gun propellants are examined microscopically for porosity, are tested for mechanical characteristics, and fired in closed bombs to determine the burning characteristics. 

K. Adas, A. Method of Computing Web for Gun Propellant Grains from Closed Bomb Burning Rates, memo report 73, Naval Powder Factory, U.S. Navy, Indian Head, Md., 1954. 

Fig. 2. Effect of grain shape on surface exposed during burning of gun propellants. Cross section of grains are shown.

Gun propellants have traditionally been fabricated from nitrocellulose-based materials. These fibrous materials can be manufactured in granular or stick forms (grains)... 

These double-base propellants are best known as smokeless propellants used in guns and rockets. Two major ingredients are used to formulate the double-base propellant grains NG and NG. As covered in Section 4.2.2, NG is a nitrate ester characterized by -O-NO2 groups, and is known as a high explosive. Since NG is a liquid at room temperature, it is absorbed by NG and serves to gelatinize the latter to form... 

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