1、MIL-K-71129 (4) W 999990b 2028308 530 m INCH-POND MIL-K-71129 (AR) AMENDMENT 4 17 December 1996 SUPERSEDING AMENDMENT 3 23 April 1996 MILITARY SPECIFICATION KIT, REFURBISHMENT, FOR CARTRIDGE, 81MM PRACTICE, SHORT RANGE, M880 LOADING, ASSEMBLING AND PACKING This amendment forms a part of MIL-K-71129
2、(AR), dated 26 May 1992, and is approved for use by the U.S. Army Armaments Research, Development and Engineering Center, and is available for use by all Departments and Agencies of the Department of Defense. PAGE 3 3.3 : Delete: “propelling charge“, and substitute: “ignition cartridge“. Delete 3.6.
3、1 in its entirety and substitute: “3.6.1 Misfires. The cartridges shall not fail to fire from the weapon when they are initially dropped into it.“ * Delete 3.6.2 in its entirety and substitute: “3.6.2 Short rounds. Cartridges having a horizontal range less than 80 percent of the average horizontal r
4、ange (calculated without the short rounds) will be classified as a short round. I Delete 3.6.4 in its entirety and substitute: “3.6.4 Ranse and deflection Precision. The cartridge shall have a horizontal range probable error (PEr) less than 15 meters, for all zones when calculated to the nearest one
5、 tenth (0.1) meter. The deflection probable error (PEd) shall be less than 15 meters for all zones when calculated to the nearest one tenth (0.1) meter.“ 1 of 9 AMSC N/A FSC 1315 DISTRIBUTION STATPHENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reprodu
6、ction or networking permitted without license from IHS-,-,-MIL-K-71129 (AR) AMENDMENT 4 J PAGE 4 3.6.6: Add: “unobstructed“, before the word “flight“. 3.6.9 Add the following: 3.6.9 Dud pluu function. “3.6.9.1 Functioned round. All dud plug heads (regardless of stems) shall blow out of the projectil
7、e body upon fuze function.“ “3.6.9.2 Inert round. No dud plug head (regardless of stems) shall exit the projectile body during ballistic flight or upon impact.“ 3.9 Add the following: “3.9 Dud pluqs.“ “3.9.1 Confiuuration. Three dud plugs properly inserted into the projectile body ground test. I sha
8、ll be present and for the proving “3.9.2 Dud plu4 push in - push out force. No dud plug shall push into the required test plate using a force greater than 40.0 pounds and shall not be capable of being pushed out of the required test plate using a force of less than 25.0 pounds at a temperature of 70
9、 degrees F 2 -3 degrees F when tested as specified in 4.5.4.“ PAGE 6 * 4.3.3(b), Add after first sentence: “Graze impact duds shall not be counted for score. These shall be recorded for information only and shall be x-rayed to document that the fuze was armed. Side impact duds shall be recorded for
10、information only and x-rayed to document that the fuze was armed. If more than four side impacts occur, the first article sample represented by the sample shall be referred to the technical agency for disposition. In either of the above cases, if the x-ray reveals that the fuze did not arm, the fuze
11、 shall be considered to be a dud.“ * Delete *c“ in its entirety and substitute: “c. One or more short rounds occur at +110 degrees F or +70 degrees F. Two or more short rounds occur at O degrees F.“ 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M
12、IL-K-71129 (q) 9999906 2028110 199 MIL-K-71129 (AR) AMENDMENT 4 PAGE 6 (cont) Delete “g“ and “h“ in their entirety and substitute: “g. If the weapon is damaged by abnormal wear of the interior or of the firing pin, or caused by excessive pressure.“ “h. Two or more improper impact signatures occur.“
13、Add the following: Il i . All three dud plug heads (regardless of stems) are missing from the projectile body in the inert fuze ballistic test. “j. Two or more dud plug heads (regardless of stems) fail to exit projectile bodies (accumulatively, i.e., two remaining in a single projectile or one each
14、remaining in two projectiles) in the live fuze ballistic tests (except in the case of a particular round that was an actual dud, in which case paragraph i .It above applies) .It PAGE 7 Table I: Proving ground test line, under Conformance Criteria: Delete: 1721, and substitute: “96“. Add the followin
15、g: “Dud Plug . . . (dwg. 12961001) Examination for defects . 30 . 3.1 . 4.4.2.11 Push in - push out test . 30 . 3.9.2 . 4.5.4ll. PAGE 9 4.4.1: Delete the word “interfix“ from the text from lines a., b., c., and d. Add the following: “e. Dud plugs from one inspection lot that comply with 3.9 -2. 3 Pr
16、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-PAGE 11 4.4.2.1, Major 105: Change call out: from: “Length of large outside diameter section“, to: “Length between large outside diameter aft face to firing pin point“. PAGE 15 4.4.2.5: Delete Special A i
17、n its entirety. Critical: Add the following: 1 Fuze striker in armed position . 100% . 3.1 . Visual“. PAGE 16 4.4.2.6: Delete Major 103 in its entirety. PAGE 20 4.4.2.10: Delete Specials A, B, C, D, E, F and G in their entirety and add the following: 4 Provided by IHSNot for ResaleNo reproduction or
18、 networking permitted without license from IHS-,-,-MIL-K-7Li29 (4) 9999906 2028ii2 Tbi = MIL-K-71129 (AR) AMENDMENT 4 r bRAWING NUMER 12961001 PARAGRAPH ITLE 1NEXT HIGHER ASSEIIBLY “4.4.2.11 Dud Plug SHEET 1 OF CONFORMANCE REPUIREMENT INSPECTION METHOD CIASSIFICATION EXAMINATION OR TEST CRITERIA PAR
19、AGRAPH REF ER EN C E Critical None defined PAGE 21 Maior 101 Push in - push out test 30 3.9.2 Test/4.5.4 L.l.LlIVL I 201 poor workmanship I t hn:, I I I I I I I 30 3.6 Visual“ 4.4.3.1: Delete in its entirety and substitute: “4 4.3.1 Provins mound test. 4.4.3.1.1, Add: “The refurbished cartridges sha
20、ll be observed for the following characteristics: a. b. d. e. f. 9. h. i. C. j. Misfires, major defect (see 3.6.1) Duds, major defect (see 3.6.5) Short rounds, major defect (see 3.6.2) Premature burst, critical defect (see 3.6.6) Metal parts separation, major defect (see 3.6.3) Precision, major defe
21、ct (see 3.6.4) Weapon damage, major defect (see 3.6.7) Improper impact signature, major defect (see 3.6.8) All dud plug heads out of any one projectile in the inert fuze ballistic test, Critical defect (see 3.6.9.2) Two or more dud plug heads remain in the live fuze ballistic test, Major defect (see
22、 3.6.9.1)“. 4.4.3.1.2, Add: “i. All three dud plug heads (regardless of stems) are missing from the projectile body in the inert fuze ballistic test. j. Two or more dud plug heads (regardless of stems) fail to exit projectile bodies (accumulatively, i.e., two remaining in a single projectile or one
23、each remaining in two projectiles) in the live fuze ballistic tests (except in the case of a particular round that was an actual dud, in which case paragraph “i. above applies) . 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-K-71129 (4) m 999
24、9906 2028113 9T m MIL-K-71129 (AR) AMENDMENT 4 * 4.4.3.1.2(b), Add after first sentence: “Graze impact duds shall not be counted for score. These shall be recorded for information only and shall be x-rayed to document that the fuze was armed. Side impact duds shall be recorded for information only a
25、nd x-rayed to document that the fuze was armed. If more than four side impacts occur, the lot represented by the sample shall be referred to the technical agency for disposition. In either of the above cases, if the x-ray reveals that the fuze did not arm, the fuze shall be considered to be a dud.“
26、* 4.4.3.1.2(c), Delete in its entirety and substitute: 11 c. One or more short rounds occur at +110 degrees F or +70 degrees F. Two or more short rounds occur at O degrees F.“ PAGE 22 Add the following: “d. One group of 24 each with inert fuzes conditioned for at least 24 hours at O degrees F +/- 2.
27、5 degrees F (see 4.4.3.1.2), shall be fired at charge 3.“ 4.5.1.1, last paragraph: Delete and substitute: “The individual deflections and ranges (accuracy of both to 0.01 meter) and muzzle velocities shall be calculated to the nearest 0.1 meter and recorded on the firing record for groups a, b, and
28、c above. All rounds shall be fired onto a flat, nongrassy earthen surface that is not marshy or frozen.“ PAGE 23 Add the following: “4.5.4: Push in - push out test. Major defect. A hardened steel test plate of 1 x 2 x 1/4 inch is required for this test. There is to be a 0.250 2 .O01 diameter thru ho
29、le (having an internal surface finish of 32 maximum) in the steel plate. The sample of dud plugs to be tested shall be preconditioned at a temperature of 100 degrees F 2 5 degrees F for a period of not less than 24 hours nor more than 48 hours prior to being subjected to this test. The preconditione
30、d dud plugs shall be tested not earlier than 15 minutes after removal from the 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-K-71129 (4) 0b 2028114 834 MIL-K-71129 (AR) AMENDMENT 4 PAGE 23 (cont) conditioning box nor later than one (i) hour a
31、fter removal from the conditioning box. Press a sample dud plug into the hole using an arbor press until the head is 0.0625 t 0.02 inch above flush with the plate surface. At this point, the push in test is completed. Record the maximum force. Turn the steel plate over and push the dud plug out of t
32、he steel plate to 0.0625 2 0.02 inch above flush using the same arbor press. Record the maximum force required to push out the dud plug. At this point, the push out test is completed. Compute sample mean (xbar) and standard deviation (sd). Insert these into the following formulas: Accept if: a. xbar
33、(1n) = 37.0 pounds max., xbar(1n) + 3sd(In) = 40.0 pounds max. and b. xbar(0ut) = 30.0 pounds min., xbar(0ut) - 3sd(Out) = 25.0 pounds min. and no individual x(0ut) less than 25.0 pounds. Any dud plug sample that does not meet the above requirements shall be cause for lot rejection. Each test sample
34、 quantity may be examined for outliers (high side only) using the Grubbs T statistical test (see 6.12). A maximum of two outliers may be removed from the sample quantity.“ PAGE 25 6.10 Delete in its entirety. 6.11 Add the following: “6.11 Inspection lot definition. A homogeneous collection of units
35、of product or one shipment of component parts or assemblies from a subcontractor, bearing identification and treated as a unique entity from which a sample is to be drawn and inspected (and tested) to determine conformance with the acceptability criteria.“ 7 Provided by IHSNot for ResaleNo reproduct
36、ion or networking permitted without license from IHS-,-,-PAGE 25 (cont) 6.12 Add the following: “6.12 Outlier test. When the accept criteria is not met and if it is suspected that a statistical outlier may be present in the sample of 30 observations. Arrange the observed values in order of increasin
37、g magnitude (Xi, X2 Xn-1, Xn. Using the statistics calculated for the sample, calculate Tn where : If X1, the smallest value, rather than Xn, is the doubtful value the test criterion is: - Tn = Xn - X S If X1, the smallest value, rather than Xn, is the doubtful value the test criterion is: - T1 = X
38、- X1 S Where : - arithmetic average of all n values estimate of the population standard deviation based on the sample data calculated as follows: - X S - If Tn is less than or equal to 2.745, the highest value may not be eliminated. The lot is rejected. If Tn is greater than or equal to 2.745, the l
39、argest value obtained in the sample shall be eliminated and the sample statistics X and s shall be recalculated using the twenty-nine remaining values. This shall be compared to the accept criteria. If the criteria is met, accept the lot. If not, the same procedure shall be followed for the Xn-1 obs
40、ervation. Calculate Tn-1 based on the new statistics of the remaining sample of 29. If Tn-1 is less than or equal to 2.730, the lot is rejected. If Tn-1 is greater than or equal to 2.730, then this observation shall be eliminated and the sample statistics calculated based on the remaining 28 observa
41、tions. If these values meet the accept criteria, accept the lot. If the accept criteria is still not met, reject the lot.“ 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-K-7 11 2 9 (AR) AMENDMENT 4 PAGE 25 (cont) 6.13: Add the following: “6.13
42、 Marshy around. Marshy ground is defined as an earthen surface that contains standing water or free flowing (fluid) mud or a combination of both. 6.14 Add the following: “6.14 Frozen around. Frozen ground is defined as an earthen ground within which water has frozen creating a hard surface .“ * Add
43、the following paragraphs: “6.15 Graze impact dud. A graze impact dud is a fuze dud caused solely by the fuze hitting an object in the impact area (e.g. rocks) on its side and damaging the fuze prior to ground impact. This shall be determined by the proving ground test director based on his examinati
44、on of the rounds point of impact. 6.16 Side impact dud. A side impact dud is a fuze dud caused solely by the cartridge impacting on its side (without the fuze hitting an object prior to ground impact where the fuze striker shows no evidence of impact. This shall be determined by the proving ground t
45、est director based on his examination of the rounds point of impact.“ The margins of this amendment are marked with an asterisk, or vertical line to indicate where changes (additions, modifications, corrections, deletions) from the previous amendment were made. This was done as a convenience only an
46、d the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous amendment. Custodian: Army-AR Preparing activity: Army-AR (Project 1315-0160) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
