NAVY MIL-C-18835 C-1968 CARTRIDGES 20MM FOR AIRCRAFT GUNS MK 11 AND MK 12《MK 11 和MK 12高射炮用20毫米炮弹》.pdf

1、MIL-C-l835C 13 444770b 0299904 i W MIL-C-1883% (AS). 19 August 1968 Superseding . NAVORD 18 December 1958 MIL-C-18835B MILITARY SPECIFICATION CARTRIDGES, 20MM, FOR AIRCRAFT GUNS MK 11 AND Mi Incendiary Ignition (API 1 Function APT, 1.20 mils, TP 1.39 mils R .33 milliseconds Indiv. R 3.3 Tracer cup s

2、epara- tion: Accept on O reject on 1 Dud (burning time less 1.1 sec): Accept on 3 reject on 4 Accept 1 reject 2 Accept 1 reject 2 Table I 20 Accept O reject 1 10 Accept O reject 1 of a misfire an additional round shall be fired in lieu of and the number of rounds fired for functioning and casualty W

3、ill be equally divided for firing in both MK 11 and MK 12 Guns, L Assembled projectiles only , to be furnished in. this sample. Additional components will be supplied by the Test Activity. 4i111 means that all cartridge types covered by this specification will be subjected to this test. means that t

4、he test is for that type of cartridge only. The designation of a particular type (API, HEI, etc.) li. 3 Iaspection 4.3.1 Place. Unless otherwise specified, the sanpling inspection, and tests of armunition shall be iriade at the place of manufacture by personnel employed and furnished by the Governme

5、nt. such as necessary floor space, tables and benches. L_ The supplier shall provide adequate facilities, 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-1683 5C (AS) AMMUNITION DATA CARD - =ED AMMUNITION Caliber: ZOXM Amm. Lot No: For Gum: C

6、omplete Round Drawiug No: Powder Index: SPDN Charge Weight: BrU7Ae Velocity: (Automatic 8290 to 8360 fps) Prenre (Cu.) O Order No: Ctg. Mk. Mod. Packed: inabox Componente Prinier Caiidgz csr;? Fropellait Powder Type: Qpmtity in Lot: Job Order No: - - - Year Date Drawing or - Number Mfd. Loaded Wumbe

7、r Manufactum Descriptii Lot -I- - _-_ -. - Pro jectib _- REMARKS: Figure 1 4.3.2 of the plants where work for the Government is being done at any time when such work is in progress and shall be allowed to observe and check any and all pro- cessing operations and prepar tions for shipment without int

8、erfering with pro- duction. Plant Access. The Government shall be allowed access to those parts 4.3.3 Component Assurance. Before the components are assembled into car-. tridges and after such components have been withdrawn from store and stock on hand, the Government shall, without interfering with

9、 production, assure in such manner as appears practicable that the components are suitable in all respects for assembly into satisfactory cartridges. Tests. Compliance with the requirements specified herein is mandatory 4.4 prior to acceptance, by the Government, of lots represented by the samples s

10、ub- mitted for testing. Failure to comply will result in rejection of the lot. - 4.4.1 Electrical Resistance Test. The electrical resistance of each primed cartridge case, measured with a circuit approved by the Government shall not be less than 1000 nor more than 5,000,000 ohms. Instrumentation sha

11、ll be of the Miltheter AN/PCM-4 me or equivalent, designed to pass a maximum current of 25 milliamperes when the test leads are shorted. 10 o Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-18835C (Ab) 4.4.2 be tested in a tensile test machine

12、or equivalent machine of suitable capacity which will register accurately the force required to extract the projectile from the cartridge case, after it has been crimped, when the rate of travel of the test head is controlled within 0.125 to 0.25 inch per minute, inclusive. Lot acceptance or rejecti

13、on in respect to requirement of 3.5 shall be judged in accordance with the double sampling plan outlined below (AQL 0.30%): Projectile Extraction Test, Each cartridge from the test sample shall Sample Cumulative Accept Reject Sample Size Sample Size Number Number 1st 50 50 O 2 2nd 100 150 1 2 The re

14、sults are to be recorded. 4.4.3 shall conduct the following tests to insure compliance with 3.7: Ballistic Tests. The test activity selected by the procuring agency 4.4.3.1 Velocity. at random from all of the ammunition boxes in which the samples were shipped and fired for velocity from the automati

15、c test weapons specified in 4.7, instrumentation is not available at the test facility for measuring velocities when firing fully automatic, the test may be conducted in any test weapon speci- fied in 4.7. A-625. Publication ORD-M608-PMY Vol, III and AMCR 715-505, Vol. 8. Ten ref- erence or control

16、rounds shall be assembled by the test activity from selected components and master propellant and interspersed with the last twenty test cartridges. The corrected average velocity, standard deviation and rate of fire of the last 30 rounds of the burst shall be computed for conformance with 3.7,1, Th

17、e first five rounds are to be considered warming rounds. corrected velocity for the test cartridges shall be computed by the following formula : Twenty-five cartridges of the test sample shall be selected If adequate The method of test shall be in accordance with specification MIL- The average V=lt

18、(V2-V3 ) when V1=Corrected muzzle velocity measured on 20 test cartridges. V2=Assigned muzzle velocity of the propellant used in reference VfAverage muzzle velocity measured on 10 reference cartridges in cartridges. the test weapons. When the velocity test results do not meet the criteria, chamber p

19、ressure test- ing shall be performed in accordance with 4.4.3.4. 4.4.3.2 Waterproof Velocity. randomly selected and submerged in water for 24 hours in accordance with Publi- cation ORD-M608-PM, Vol. III and AMCR-715-505, Vol. 8. . The rounds are then to be fired from the same test weapon specified i

20、n 4.7. Ten reference rounds as described in 4.4.3.1 shall be fired from the same weapon and on the same day as the test cartridges. shall be computed for conformance with 3.7.2. will be computed from the formula in 4.4.3.1. Twenty cartridges of the test sample shall be The corrected average velocity

21、 and standard deviation The corrected average velocity 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_- - - MIL-C-LB835C 13 m 7797706 0277920 b m MIL-C-18835C (AS) 4.4.3.3 Action Time. merged in water for 24 hours prior to firing. on the basis o

22、f single action firing of four subsets composed of five rounds each in a test weapon (see 4.7). fired and a range value (R) shall be determined for each subset. round (R) shall then be computed as follows: Twenty test sample cartridges shall be selected and sub- Action time shall be evaluated Subset

23、s shall consist of rounds in the order The average -R +R tR tR R-1 2 3 4 4 Where each of the R1 through R4 values represents the range of a subject of given readings. In the event the requirements of 3.7.3 are not met, another twenty round sample (not subjected to water) shall be fired for conforman

24、ce with 3.7.3. The test may be conducted in conjunction with 4.4.3.2. 4.4.3.4 a pressure barrel in accordance with publication ORD-M608-PMY Vol. III and AMCR 715-505, Vol. 8. be fired. the barrel by the .following formula : Pressure Firing. Each cartridge of the test sample shall be fired in At leas

25、t 3 warming rounds, same as those tested, shall The average peak pressure shall be corrected for the condition of P =Corrected peak pressure of the test cartridge; Pl=Average peak pressures measured on test cartridge. P,=Assessed pressure of referenced cartridges. Pb=Average pressure of 10 reference

26、 cartridges in the pressure barrel. This firing of the reference round sample shall be interspersed throughout testing. This test to be performed only in the event of failure in velocity firing test or waterproof velocity firing tests, 4.4.3.1 and 4.4.3.2. 4.4.3.5 Accuracy Firing. determine the aver

27、age disposition value from an accuracy barrel as specified in 4.7 at a vertical target placed at a distance of at least 500 yards. warming rounds should be shot if the gun is cold. fired at a uniform rate. and horizontal patterns of the impacts on the target shall be determined. average pattern (I)

28、shall be computed as follows: Two groups of ten cartridges each shall be fired to Three The test rounds shall be For each group of ten cartridges fired, the vertical The -P tP tP +P P- 1 2 3 4 where 4 P1=The longest vertical distance in inches between any two impacts of the first group of ten rounds

29、 fired. Pq=The longest horizontal distance in inches between any two impacts of the first group of ten rounds fired. P3=The longest vertical distance in inches between any two impacts of the second group of ten rounds fired. 12 Provided by IHSNot for ResaleNo reproduction or networking permitted wit

30、hout license from IHS-,-,-MIL-C-1883 5C(AS) P4 = The longest horizontal distance in inches between any two impacts of the second group of ten rounds fired. All measurements shall be made from center of impact holes. tern (P) shall be converted to mils as follows: The average pat- M=PX 1000 where - d

31、 d = The distance in inches from the gun muzzle to the target, The average mil value (M) computed as specified should not exceed the average mil limit specified in 3.7.3 for each cartridge type. average mil value (M) shall be reported for information purposes, The 4.4.3.6 Tracer Functioning. selecte

32、d and submerged in water 24 hours prior to firing. be fired from any test weapon specified in 4.7. thrown tracer cups shall be placed near the gm muzzle. is 1/4“ pressed paper board (4 x Y) placed at a distance of 15 to 30 feet from the gun muzzle. Gun elevation shall be such that complete burning o

33、f the tracer can be observed prior to impact of the projectile, binoculars and stop watches with sweep second hands should be used to insure . that complete and accurate times are obtained. of duds and tracer cup separations shall be recorded and computed as necessary to determine conformance with 3

34、.7.5. Lot disposition for duds shall be determined in accordance with the AQL of 4.0% defective of MIL-STD-105, single sampling plan. Lot disposition for burning time less than 1.1 seconds shall be determined in accordance with an AQL of 6.5% defective of MIL-STD-105, single sampling plan. This test

35、 may be conducted in conjunction with 4.4.3.2, Twenty cartridges from the test sample shall be The cartridge shall A suitable screen to detect A suitable material Suitable aids such as All burning times, the number 4.4.3.7 Fuze Sensitivity. samples and submerged in water for 24 hours prior to firing

36、. shall be fired from any test weapon specified in 4.7 for conformance with 3.7.6. num plate (AL-2024-T3, QQ-A-250/4) normal to the line of fire at a range of 150-300 feet. Each projectile shall impact at least three inches from pre- vious impact perforations. with an AQL of 4.0% defective of MIL-ST

37、D-105, single sampling plan. this test may be conducted with 4.4.3.2. 4.4.3.8 Incendiary Ignition. samples and submerged in water for 24 hours prior to firing. be fired from any test weapon as specified in 4.7 to impact against an aluminum alloy (AL-2024-T3) target 1/16 to l/8lt thick normal to the

38、line of fire at a range of 125-300 feet for conformance with 3.7.6. of 1/4 inch with kerosene shall be placed approximately 3 inches behind the target and parallel to and not more than 6 inches below the projected line of fire. Observations shall be made to determine whether or not a projectile impa

39、cted on the target produces ignition of the kerosene. will be final in determining whether or not ignition occured on impact, disposition shall be determined in accordance with an AQL of 4.0% defective of MIL- STD-105, single sampling plan. conjunction with 4.4.3.2. 4.4.3.9 Twenty cartridges shall b

40、e selected from the test The cartridges The projectile must impact against a target of 0.032 inch thick alumi- Lot disposition shall be determined in accordance When feasible, Twenty cartridges shall be selected from the test The cartridges shall A 12-inch square tray filled to a depth The decision

41、of the test director Lot When feasible, this test may be conducted in General Function and Casualty Test. Cartridges of the test sample 13 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-1883 5C (As) shall be fired, fully automatic, in either o

42、r both automatic weapons specified in 4.7. Suitable targets must be located to detect any metal parts separation or break-up of the projectile assembly. ance with sub-section 7-15 of Publication ORD-M608-PM9 Vol. III and AMCR 715- 505, Vol. 8. submitted for ballistic acceptance, fifty (50) cartridge

43、s shall be temperature conditioned at t165OF and fifty (50) cartridges shall be temperature conditioned at -65OF for a minimum of two hours prior to firing. Temperature conditioning need apply only to firings in the MK 12 gun. should be maintained throughout the testing to insure conformance with 3.

44、7.9. 4.4a3.10 Safety. The projectiles furnished for this test shall be assembled into cartridges by the testing activity utilizing station component; and a propellant charge that would produce a chamber pressure of 68,000 plus or minus (t) 2000 p.s,i. (copper) in a new gun at t7OoF. fFom any test we

45、apon as specified in 4.7. to a point of impact at least 2500 yards from the gun for premature bursts, pre- mature ignitions, and tracer cup separations shall be noted and reported. In general the test shall be in accord- From the test samples of the pilot lot and all production lots A record of all

46、discrepancies The cartridges shall be fired Also projectiles shall be observed 4.4.3.11 Drop. nose down, onto a steel plate from a height of 40 feet for conformance with 3.9. Ten cartridges selected from the test samples shall be dropped 4.5 Government are found to be the cause of failure or malfunc

47、tioning of the cartridges, such cartridges shall be held for disposition by the procuring agency, who will direct such tests as are considered necessary to determine the final disposition of such cartridges, 4.6 Retests. The authorization for retest and/or additional testing, and the number of round

48、s to be tested, will depend on the circumstances of the individual case, and will be at the discretion of the procuring agency. 4.7 ducting ballistic tests requiring automatic fire shall be known to render satisfactory performance and in all respects shall be equivalent to the current service weapon

49、s. Sufficient Check-out rounds should be fired to determine weapon performance. viously accepted ammunition lot or reference rounds. The guns selected for velocity firing test 4.4.3.1 shall be equipped with barrels which will give an average muzzle velocity of not more than 100 feet per second below that ob- tained from an average new barrelnf the type being used. The muzzle velocity shall be determined by firing a minimum of 10 reference rounds. The test weapons