MIL-P-81994

Abstract

This specification covers propellant for use in ammunition for the 20MM Naval Aircraft Guns, MARK 11 and MARK 12. As used in this document, the word "powder" is synonymous with "propellant." <b><u>Intended Use:</u></b> This propellant is designed for use in ammunition for 20MM Naval Aircraft Guns, MARK 11 and MARK 12. These Mann barrels shall be subjected to a test of six master powder rounds (5 data rounds) (see <a>3.6.1.2</a>). All of the rounds of a burst shall be included in cyclic rate computations, but the first round of each burst is considered a conditioning round and shall not be included in velocity computations. The 20MM MARK 11 machine guns used in acceptance testing of powder shall be assembled in accordance with the drawings listed on LD 522056. The MARK 11 machine gun shall be subjected to a burst of 101 master powder rounds (see <a>3.6.2.1</a>). The 20MM MARK 12 MOD 0 guns used in acceptance testing of powder shall be assembled in accordance with the drawings listed on IL 2838594 with the feeder switch installed. The MARK 12 gun shall be subjected to a burst of 25 master powder rounds (24 velocity data rounds) (see <a>3.6.2.2</a>). MARK 11 projectiles from a previously accepted production lot shall be screened, and selected projectiles shall weigh 1700 &#177; 5 grains and conform to the drawings listed on DL 2176062-1. Cases shall be MARK 5 MOD 0 cases from a previously accepted production lot and conform to the drawings listed on DL 517534. Cases used for firings in the Mann barrel (cu) shall be modified to facilitate the taking of pressure. The case shall have been drilled with a No. 19 (0.166 inch) drill 2.10 &#177; 0.010 inch from centerline of the hole to the base of the case. The drilled hole shall be covered with a piece of cellulose tape of sufficient size to assure positive sealing. Cases used for firings in the Mann barrel (piezoelectric) shall be modified to facilitate the taking of pressure. The case shall have been drilled with a No. 19 (0.166 inch) drill 3.055 &#177; 0.010 inch from centerline of the hole to the base of the case. The drilled hole shall be covered with a piece of cellulose tape of sufficient size to assure positive sealing. M52A3B1 primers from a previously accepted production lot shall be used, preferably not more than 2 years of age, and shall conform to MIL-P-1394 and D7548066. <br>