1、LzIl INCH-POUND MIL-C-71138 (AR) AMENDMENT 1 29 August 1995 MILITARY SPECIFICATION CARTRIDGE, 25MM ARMOR PIERCING DISCARDING SABOT TRACER, M791 This amendment forms a part of MIL-C-71138 (AR), dated 4 January 1994, and is approved for use by the US Army Armaments, Research, Development and Engineeri
2、ng Center, and is available for use by all Departments and Agencies of the Department of Defense. PAGE 4 3.12, Delete in its entirety and substitute: “3.12 Function, casualtv and metal parts security. The cartridge shall function without casualty or hazards when conditioned and fired from the 25mm M
3、242 Weapon at 200 spm. For lot acceptance testing, the cartridges shall be conditioned to ambient temperature. For First Article tests, one half the sample shall be conditioned to -54C and the other half to +7loC. The cartridge shall exhibit metal parts integrity in the weapon feed mechanisms (chuti
4、ng, feeding and chambering). Components designed for separation such as the sabot, protective cap and base are excluded (see 4.6.8) .I1 PAGE 13 4.4.2.3, Critical 1, Delete in its entirety and substitute: “1. Split or perforated case 100% 3.1 Visual L/“ 4.4.2.3, Add the following criticals: “2. Crimp
5、 missing (case/projectile) 100% 3.1 Visual L/ 3. Low propellant charge (25% below established charge weight) 100% 3.1 Gage 11 AMSC N/A 1 of 3 FSC 1305 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Licensed by Information Handling Services - MIL-C-71138 (1) m 99999
6、06 2007886 603 m MIL-(2-71138 (AR) AMENDMENT 1 PAGE 14 4.4.2.3, Sheet 2 of 2, delete Note 1, in its entirety. PAGE 19 Add Fig1 title to table: “Table IV Firing Defects“ PAGE 21 re 1, Item J, Delete “NO closer than 1/4 Anch“ and substitute “NO closer then 1/4 inch to extractor groove“ PAGE 23 4.6.8,
7、Delete in its entirety and substitute: “4.6.8 Function, casualty and metal parts security. The cartridges shall be tested in accordance with AS12013566, Section 11. The M242 Weapon used shall have a barrel with greater than 4,000 rounds fired through it. A vertical witness screen shall be positioned
8、 approximately 60m to 200m normal to the line of fire such that metal part failure data may be obtained. The cartridges shall be conditioned for a minimum of four hours at -54“ + 3“C, 21“ 2 3“C, and 71“ i 3C. When ambient temperature conditins are 20“ 2 lO“C, testing for the 21“ 2 3C group can be at
9、 range ambient conditions. All firings shall be at 200 2 50 spm in bursts of 21 to 28 rounds. The weapon shall be cooled to ambient temperature after each temperature and range group test is completed (100 maximum cartridges fired after which cooling to ambient is required.). The witness screen shal
10、l be examined during the cooling period for fragment imprints and metal parts security failures. Evidence of yaw or other erratic flight characteristics shall be recorded and evaluated for cause. Witness screen replacement shall be provided as needed. Firing defects specified in Table IV shall also
11、be determined during the cooling period. Any weapon stoppages obtained shall be recorded and evaluated for cause. Firing defects in excess of the quantities listed in Table IV shall be cause for rejection of the lot. The lot shall be rejected if 20% of the rounds fired exhibit more than 15 degrees yaw. 2 Licensed by Information Handling ServicesMIL-C-7LL38 (1) M 0b 2007887 54T MIL-C-71138 (AR) AMENDMENT 1 PAGE 25 6.7, From formula, Delete “(XI - X)“ and substitute “(XI - E)“. Custodian: Army-= Preparing Activity: Army-AR (Project 1305-0118) 3 Licensed by Information Handling Services
