DTL 12967862.pdf

DTL12967862

W/AMENDMENT 5

CAGE CODE: 19200

3 December 2007

SUPERSEDING

W/AMENDMENT 4

CAGE CODE: 19200

12 February 2007

DETAIL SPECIFICATION

ITEM SPECIFICATION

FOR THE

CARTRIDGES, 120MM, ILLUMINATING, M930,

AND IR M983

LOADING, ASSEMBLING AND PACKING AND PARTS FOR

U.S. Army ARDEC Picatinny Arsenal, NJ 07806-5000

Prepared by

Quality Engineering & System Assurance Mortars & Smart Munitions Group – AMSRD-AAR-QEM-C

FSC: 1315

DISTRIBUTION STATEMENT A. Approved for public release;

distribution is unlimited.

This cover page must be part of the specification copy.

1. SCOPE

1.1 Scope. This specification establishes the

requirements for two types of illuminating cartridges designated as Cartridges, Illuminating, M930/M983 for the 120mm Mortar System.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are

specified in sections 3 and 4 of this specification. This section does not include documents in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all requirements cited in sections 3 and 4 of this specification.

2.2 Government documents.

2.2.1 Specifications, standards and handbooks. The following

specifications, standards and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issue of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation (see 6.2).

STANDARDS

FEDERAL

FED-STD-595 Colors Used In Government Procurement

DEPARTMENT OF DEFENSE

MIL-STD-1916 DOD Preferred Methods for Acceptance of Product

SPECIFICATIONS

FEDERAL

TT-E-516 Enamel, Lustreless, Quick-Drying Styrenated Alkyd Type

DEPARTMENT OF DEFENSE

MIL-P-223 Powder Black

DTL12977364 Detail Specification for the Cartridge, Ignition, M1020 for 120mm Mortars M120 and M121

(Unless otherwise indicated, copies of the above specifications, standards, and handbooks are available from the Standardization Documents Order Desk, 700 Robbins Avenue, Bldg. 4D, Philadelphia, PA 19111-5094.)

2.2.2 Other Government documents, drawings, and

publications. The following other Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation.

DRAWINGS (See 6.4)

U.S. ARMY TACOM ARMAMENT RESEARCH, DEVELOPMENT AND

ENGINEERING CENTER (TACOM-ARDEC)

PRODUCT DRAWINGS

12577503 Cartridge 120MM, Illuminating - M930 12967862 Cartridge, 120MM: IR Illuminating - M983

PACKAGING DRAWINGS

12577509 Container, Ammunition, Fiber, PA153 for Cartridge, 120mm Mortar XM929, M929, M930, M933, M934, M934A1 and M983 12577551 Packing and Marking for Container, Fiber, PA153 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983

12577569 Container, Metal, Shipping and Storage, Cartridge 120mm Mortar, PA154 12577570 Packing and Marking for Container, Metal, PA154 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983 12577571 End Plate, Plywood 12577573 Corrugated Fiberboard, Wide 12577574 Corrugated Fiberboard, Narrow

(Copies of other Government documents, drawings and publications required by contractors in connection with specified acquisition functions should be obtained from U.S. Army TACOM-ARDEC, AMSTA- AR-QAD, Picatinny Arsenal, NJ 07806-5000)

2.3 Order of precedence. In the event of a conflict

between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

3. REQUIREMENTS

3.1 First article. When specified in the contract or

purchase order (see 6.2 ) a sample shall be subjected to first article inspection in accordance with the technical provisions herein (see 4.3)

3.2 Materials. Materials shall be in accordance with

drawings 12577503, 12967862, and specifications.

3.3 Components and assemblies. The components and

assemblies shall comply with all requirements specified on drawings 12577503 and 12967862, all associated drawings, and with all requirements specified in applicable specifications and standards.

3.4 Moisture content of black powder in expelling charge

assembly. The moisture content of the black powder used in the expelling charge assembly, at the time of loading, shall not exceed 0.5 percent.

3.5 Leak test for ultrasonically welded expelling charge

cup. The expelling charge cup, when ultrasonically welded in accordance with drawing 12967868 shall be able to withstand the leak test.

3.6 Obturator. The obturator shall be properly bonded, below flush and free to rotate after assembly. The average breaking strength of the obturators minus three standard deviations shall not be below 25 kilograms when ultrasonically welded or below 48 kilograms when bonded by adhesive.

3.7 Proving ground. The cartridge shall comply with the

following requirements.

3.7.1 Misfire. The cartridge shall not fail to fire from

the weapon.

3.7.2 Premature burst. The cartridge shall not function

in the mortar tube or in the first 100 meters of flight.

3.7.3 Security of parts. There shall be no metal part

failures in the mortar tube or in flight prior to fuze functioning.

3.7.4 Short rounds. No cartridge shall have a horizontal

range less than 80 percent of the average horizontal range.

3.7.5 Fuze functioning. The fuze shall function and expel

the payload from the cartridge.

3.7.6 Cartridge performance.

3.7.6.1 Cartridge functioning. The parachute shall deploy

and suspend the illuminant assembly during its burn time.

3.7.6.2 Visible Illumination. The cartridge shall provide

effective illumination (see 6.6 ) for a minimum of 50 seconds.

3.7.6.3 Infrared illumination. The cartridge shall

provide effective illumination (see 6.6) for a minimum of 50 seconds.

3.7.6.4 Fuze function time. The fuze shall function and

comply with the requirements in Table I.

TABLE I. Fuze function time Round Type

Temp.

(oC)

Charge Fuze Setting (seconds)

Fuze Function time (seconds)

M930 21 1 19 19 +/- 1 21 4 42 42 +/- 1

M983 21 1 18 18 +/- 1 21 4 41 41 +/- 1

3.8 Check test for deterioration of ignition cartridge. A

deterioration check test of the ignition cartridge shall be performed on each lot of ignition cartridges which have been stored under normal conditions for more than two years or under adverse conditions for any period of time.

3.9 Workmanship.

3.9.1 Parts and assemblies. All parts and assemblies

shall be free of burrs, chips, dirt, grease, rust, corrosion, and other foreign materials that may adversely affect fit or function. The cleaning method used shall not be injurious to the parts nor shall any parts be contaminated. All required markings shall be legible, neat and sharply defined.

3.9.2 Threads. Threads shall be full and undamaged for

the entire minimum length or depth as required on the applicable drawing.

3.9.3 Cloth. All cloth shall be free of tears, rips, and

foreign matter. The stitches in the cloth shall be neat and continuous without breaks, tears, or foreign matter.

4. VERIFICATION

TABLE II. Requirements/verification cross reference matrix

METHOD OF VERIFICATION

(see 6.6)

CLASSES OF VERIFICATION

1-Analysis 2-Demonstration (end item test) 3-Examination 4-Test

A- First Article B- Conformance

Verification Method

Verification Class

Section 3 Requirement

Description

1 2 3 4 A B

Section 4

3.1 First Article X X X X 4.3

3.2 Materials X X X 4.4

3.3 Components/

Assemblies X X X X 4.4.2

3.4 Moisture

content of black powder

X X X X 4.5.5

3.5 Leak test X X X X 4.5.4

3.6 Obturator X X X X 4.5.6

3.7 Proving ground X X X X 4.4.3.2

Section 3 Requirement

Description Verification Method

Verification Class

Section 4

1 2 3 4 A B

3.7.1 Misfire X X X X 4.4.3.2.4.1/

4.4.3.2.4.2

3.7.2 Premature

burst

X X X X 4.4.3.2.4.1/

3.7.3 Security of

parts

3.7.4 Short rounds X X X X 4.4.3.2.4.1/

3.7.5 Fuze

functioning

3.7.6.1 Cartridge

functioning

3.7.6.2 Illumination X X X X 4.4.3.2.4.1/

3.7.6.3 Infrared

illumination

3.7.6.4 Fuze function

time X X

X X

4.4.3.2.4.1/

3.8 Check test for

deterioration of ignition cartridge

X X 4.5.9

3.9 Workmanship X X X X 4.4.2.1-

4.4.2.24

3.9.1 Parts and

assemblies X X X X 4.5.1

3.9.2 Threads X X X X 4.5.1

3.9.3 Cloth X X X X 4.5.1

4.1 Classification of verifications. The inspection

requirements specified herein are classified as follows:

a. First article inspection (see 4.3)

b. Conformance inspection (see 4.4)

4.2 Inspection conditions. Unless otherwise specified all

inspections shall be performed in accordance with the test conditions specified in section 4 of this specification.

4.3 First article. When specified in the contract, a

sample shall be subjected to first article inspection in accordance with Table III.

4.3.1 Quantity. First article inspection shall be

performed on the quantities listed in Table III.

4.3.2 Verification to be performed. The first article

inspection shall be performed in accordance with Table III.

4.3.3 Rejection. If any item of the sample fails to

comply with the first article requirements, the sample shall be rejected.

TABLE III. First article inspection

TITLE Parts and Assembly for Cartridge,120MM, Illuminating, M930, and IR M983

SHEET 1 OF 5

DRAWING NUMBER

See below

NEXT HIGHER

ASSEMBLY

EXAMINATION OR TEST

CONFORMANCE

CRITERIA

REQUIREMENT

PARAGRAPH

INSPECTION METHOD

REFERENCE

Cup, Expulsion (dwg. 12967866) Examination for defects

O-ring (dwg. 12577638) Examination for defects

Spring, Parachute Expulsion (dwg. 12967871) Examination for defects

Base, Parachute Expulsion (dwg. 12938160) Examination for defects

Stem, Parachute, Expulsion (dwg. 12938161) Examination for defects

Plate, Parachute Expulsion Assembly (dwg. 12967870) Examination for defects

Pin, Spring (dwg. 12967877) Examination for defects

3.3

4.4.2.1

4.4.2.2

4.4.2.3

4.4.2.4

4.4.2.5

4.4.2.6

4.4.2.7

SHEET 2 OF 5

INSPECTION METHOD

REFERENCE

Plate, Baffle (dwg. 12938158) Examination for defects

Cup, Parachute (dwg. 12967872) Examination for defects

Sleeve, Loading (dwg. 12967878) Examination for defects

Pin, Shear (dwg. 12938159) Examination for defects

Plug, Screw (dwg. 12967873) Examination for defects

Cover, Expelling Charge (dwg. 12938163) Examination for defects

Cup, Expelling Charge (dwg. 12938162) Examination for defects

Expelling Charge Assembly (dwg. 12967868) Examination for defects Leak Test

Ctg., 120mm: Illum M930 Loading Assembly (During Assembly) (dwg. 12577631) Examination for defects

25 1/

3.5

4.4.2.8

4.4.2.9

4.4.2.10

4.4.2.11

4.4.2.12

4.4.2.13

4.4.2.14

4.4.2.15 4.5.4

4.4.2.16

SHEET 3 OF 5

INSPECTION METHOD

REFERENCE

Ctg., 120mm: Illum M930 Loading Assembly (Final Assembly) (dwg. 12577631) Examination for defects

Ctg., 120mm: Illum M930 (dwg. 12577503) Examination for defects Ballistic test

Ctg., 120mm: IR Illum M983 Loading Assembly (During Assembly) (dwg. 12967863) Examination for defects

Ctg., 120mm: IR Illum M983 Loading Assembly (Final Assembly) (dwg. 12967863) Examination for defects

Ctg., 120mm: IR Illum M983 (dwg. 12967862) Examination for defects Ballistic test

Container, Ammo, Fiber, PA153 (dwg. 12577509) Examination for defects

Packing and Marking for Container, Fiber, PA153 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983

(unsealed) (dwg. 12577551) Examination for defect

120 1/

25 2/

120 2/

3.7

3.7

4.4.2.17

4.4.2.18 4.5.2

4.4.2.19

4.4.2.20

4.4.2.21 4.5.2

4.4.2.22

4.4.2.23

TITLE

Parts and Assembly for Cartridge, 120mm, Illuminating

SHEET 4 OF 5

PARAGRAPH INSPECTION METHOD

REFERENCE

Packing and Marking for Container, Fiber, PA153 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, and M983 (sealed) (dwg. 12577551) Examination for defects

Container, Metal, Shipping and Storage, Cartridge 120mm Mortar, PA154 (dwg. 12577569) Examination for defects

Packing and Marking for Container, Metal, PA154 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983

(unsealed) (dwg. 12577570) Examination for defects

Packing and Marking for Container, Metal, PA154 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983

(sealed) (dwg. 12577570) Examination for defects

End Plate, Plywood (dwg. 12577571) Examination for defects 3/

4.4.2.25

4.4.2.26

4.4.2.27

4.4.2.28

TABLE III. First article inspection.

CLASSIFICATION OF CHARACTERISTICS

Parts and Assembly for Cartridge, 120MM, Illuminating, SHEET 5 OF 5

SEE BELOW

INSPECITON

METHOD REFERENCE

Corrugated Fiberboard, Wide (dwg. 12577573) Examination for defects 3/

Corrugated Fiberboard, Narrow (dwg. 12577574) Examination for defects 3/

4.4.2.29

4.4.2.30

NOTES:

1/,2/ Same cartridges may be used for these inspections and included in the ballistic samples.

3/ Dimensional inspections shall not be conducted during the First Article. Only inspections for delamination and evidence of poor workmanship shall be conducted.

4.4 Conformance inspections.

4.4.1 Inspection lot formation. Lot formation shall be in

accordance with the lot formation requirements of MIL-STD-1916, paragraph 4.2. In addition, each inspection lot of cartridges shall contain:

a. Metal parts (expulsion plates,expulsion cups) each from one lot interfix number from one manufacturer. Springs, spring pins, screw plugs, and shear pins each from one manufacturer.

b. Canister loading assemblies of one lot interfix from one manufacturer.

c. Ignition cartridges of one lot interfix number from one manufacturer.

d. Propelling charges of one lot interfix number from one manufacturer.

e. Fuzes of one lot interfix from one manufacturer.

f. Parachute assemblies from one lot interfix number from one manufacturer.

g. Obturators of one lot interfix from one manufacturer.

h. Expelling charge assemblies of one lot interfix from one manufacturer.

i. Front shell bodies of one lot interfix from one manufacturer.

j. Rear shell bodies of one lot interfix from one manufacturer.

k. Fin assemblies of one lot interfix from one manufacturer.

l. A change to the obturator ring bonding process requires a change in the cartridge lot interfix number. The use of the adhesive bonding process shall be annotated on the ammunition data card.

4.4.2 Examinations and tests.

a. For the conformance inspection paragraphs (4.4.2.1 to 4.4.2.29), the definitions of critical, major, and minor defects are provided in paragraph 3 of MIL-STD-1916.

b. Conformance examinations and tests are specified in

4.4.2.1 to 4.4.2.29.

c. The acceptance criteria for sampling inspection shall be in accordance with the levels provided in the conformance examination/test paragraph and MIL-STD-1916.

d. Alternative conformance acceptance. Unless otherwise specified herein or provided for in the contract, the contractor may propose alternate conformance procedures (see paragraph 4.1 of MIL-STD-1916).

CONFORMANCE INSPECTION

4.4.2.1

Cup, Expulsion

SHEET 1 OF 1

12967866

ASSEMBLY

12967863 12577631

CLASSIFICATION

INSPECTION METHOD

REFERENCE

Critical

Major

Minor

None defined

Outside diameter (dia.)

Overall length Depth of cavity Inside dia. of cavity True position of cavity with thread pitch dia.

Pitch dia. Of thread Major dia. Of thread Distance from face of cup to shoulder Dia. of holes (7) in base of cup Dia. of holes (6) in side wall of cup Location of holes in base of cup Distance from face of cup to end of threads Presence of burrs on threads Surface finish improper Location of holes in side of cup

Radii improper Chamfers improper Evidence of poor workmanship

VL-IV

VL-II

3.9

Gage

Visual

4.4.2.2

O-ring

12577638

ASSEMBLY

INSPECTION METHOD

Inside diameter Thickness Material certification missing or improper

100%

3.2

4.5.1

4.4.2.3

Spring, Parachute Expulsion

12967871

ASSEMBLY

INSPECTION METHOD

Free length Length at solid height Wire diameter Material certification for spring missing or improper Spring constant

Ends closed and ground

4.4.2.4

Base,Parachute Expulsion

12938160

ASSEMBLY

12967870

INSPECTION METHOD

Large outside diameter

(OD)

Small OD Thickness of large OD section Pitch diameter of thread Minor diameter of thread Distance from smaller OD surface to large OD surface Burrs in threads Surface finish improper

Radius improper Chamfer improper

4.4.2.5

Stem, Parachute Expulsion

12938161

ASSEMBLY

INSPECTION METHOD

Length of stem Outer diameter Length of pressfit cavity Diameter of pressfit cavity Small inner diameter Surface finish improper True position of press fit cavity to outer diameter

Chamfer improper

4.4.2.6

Plate, Parachute Expulsion Assembly

ASSEMBLY

INSPECTION METHOD

Length, max.

Protective finish missing Perpendicularity of stem to base face

Protective finish damaged

4.4.2.7

Pin, Spring

12967877

ASSEMBLY

INSPECTION METHOD

Length of pin Diameter of pin Material certification for spring pin missing or improper

4.4.2.8

Plate, Baffle

12938158

ASSEMBLY

INSPECTION METHOD

Outside diameter (OD) Diameter of holes (8) Location of holes (8)

4.4.2.9

Cup, Parachute

12967872

ASSEMBLY

INSPECTION METHOD

Material thickness prior to forming

4.4.2.10

Sleeve, Loading

12967878

ASSEMBLY

INSPECTION METHOD

Length

4.4.2.11

Pin, Shear

12938159

NEXT HIGHER

ASSEMBLY

INSPECTION METHOD

Diameter

Material certification for shear pins missing or improper

4.4.2.12

Plug, Screw

12967873

ASSEMBLY

INSPECTION METHOD

Pitch diameter of thread Major diameter of thread Outer diameter of head, max.

Angle of head Burrs on threads Material certification for screw plugs missing or improper

4.4.2.13

Cover, Expelling Charge

SHEET 1 OF 2

12938163

12967868

INSPECTION METHOD

Small outside diameter Cover cracked or punctured Large outside diameter True position of indentation Length (2) of indentations Width (2) of indentations Radius of snap groove Thickness of cover Depth (4) of indentations Length from shoulder to front of snap groove

CONFORMANCE INSPECTION.

TITLE Cover, Expelling Charge

SHEET 2 OF 2

4.4.2.13 12938163

REQUIREMEN

Next higher Assembly

12967868

CLASSIFICATION EXAMINATION OR TEST

INSPECTION METHOD

REFERENCE

114 Length from shoulder to rear of snap groove

VL-IV 3.3 Gage

115 Length from shoulder to rear of cover

VL-IV 3.3 Gage

116 Thickness of scored surface VL-IV 3.3 Gage 117 Diameter of snap groove VL-IV 3.3 Gage 118 True position of snap groove VL-IV 3.3 Gage 119 Angular location of indentations VL-IV 3.3 Gage

120 True position of small outside diameter

VL-IV 3.3 Gage

121 Inner diameter VL-IV 3.3 Gage

True position of inner diameter Parallelism of shoulder surfaces

201 Radii improper VL-IV 3.3 Gage 202 Evidence of poor workmanship VL-IV 3.9 Visual

Cup, Expelling, Charge

12938162

INSPECTION METHOD

Thickness of side wall and bottom Thickness of flange Large outer diameter Height of cup Cup cracked or punctured Diameter of ridge Height of ridge Length from front face to snap groove mating surface

Cup, Expelling, Charge

12938162

INSPECTION METHOD

Inner diameter of cup Diameter of snap groove mating surface Parallelism of flange surfaces True position of snap groove mating surface Width of snap groove mating surface True position of large outer diameter True position of ridge diameter

Radii improper

4.4.2.15

Expelling Charge Assembly

ASSEMBLY

12967862 12577503

INSPECTION METHOD

Weight of black powder (prior to loading) Moisture content of black powder Marking missing or illegible Cup not sealed for a full 360o Leak test Environmental conditions inadequate

1/

2/ 3/

3.4

3.5

4.5.5

4.5.4

1/ The sample shall be selected from each four hour production interval.

2/ See 4.5.4.

3/ Temperature and humidity shall be recorded continuously, and checked at the beginning and end of each shift. If conditions are not proper at either time, the quantity of product represented by the conditioning shall be rejected for further processing.

4.4.2.16

Cartridge, 120mm:

Illum M930 Loading Assembly (During Assembly)

12977631

ASSEMBLY

INSPECTION METHOD

Parachute cup missing Expulsion cup missing Closure string not removed Suspension lines pulled out of parachute bag Baffle plate missing Expulsion plate missing O-ring missing O-ring not lubricated for a full 360 degrees or not lubricated Shell body surface not lubricated for a full 360 degrees or not lubricated Loading sleeve missing or not able to be separated (i.e. taped together) Spring pin ends (2) not flush with swivel pin after assembly Riser not able to rotate freely on spring pin after being assembled Swivel assembly not centered in riser cable coils

TITLE Cartridge, 120MM:

Illum M930 Loading

4.4.2.16 Assembly

(During Assembly)

12977631

REQUIREMEN

Next higher Assembly

12577503

CLASSIFICATION EXAMINATION OR TEST

INSPECTION METHOD

REFERENCE

114 Expulsion cup not fully seated

VL-IV 3.3 Gage

115 Adhesive missing on VL-IV 3.3 Visual expulsion cup

116 Riser cable damaged during assembly

VL-IV 3.3 Visual

117 Excessive amount of VL-IV 3.3 Visual riser cable protruding from parachute bag

118 Assembly force exceeded 1/ 3.3 Gage

201 Evidence of poor VL-II 3.9 Visual

1/ For each press used, the pressure shall be measured during First Article, at the beginning of each workday, every four (4) hours during production, and for the last component prior to, and the first component after each tooling or equipment change, repair, or adjustment.

4.4.2.17

Cartridge, 120mm:

Illum, M930 Loading Assembly (Final

INSPECTION METHOD

REFERENCE

Critical I

Critical II

Screw plug missing 4/

Delete

Location of shear pin holes from front/rear body interface Shear pins missing or loose Shear pin(s) not flush or below body 1/ Gap between front and rear bodies 2/ Depth of shear pin holes 3/ Number of shear pin holes 3/ Adhesive missing on screw plug (prior to assembly) Screw plug not flush or below body surface after assembly

4.4.3.1

Visual/ Manual

1/ “Below flush” to be interpreted to mean below all surfaces of the shell body.

2/ The gap shall be measured for a full 360 degrees.

3/ In the event that a drill bit breaks or goes dull while drilling a hole, another hole may be drilled approximately 15 degrees from that hole. If a drill bit breaks in the hole, the broken drill bit shall be removed from the hole. All bare metal surfaces of the defective hole shall be touched up with paint, TT-E-516, Color No.

37875, FED-STD-595. No more than four additional holes shall be allowed (for a total of twelve holes). Through holes shall not be allowed.

4/ See paragraph 6.6.f.

Cartridge, 120mm:

Illuminating M930

SHEET 1 OF 3

ASSEMBLY

12577551

INSPECTION METHOD

REFERENCE

Critical I

A

B

Obturator ring missing 7/

Fuze safety wire missing or not properly assembled 7/ Ignition cartridge cracked or damaged to the extent that propellant will escape 7/ Fin blade distorted 7/ Propelling charge increment(s) missing, cracked, or damaged to the extent that propellant will escape 1/7/

Propelling charge increment(s) damaged but not to the extent that propellant will escape 1/ Obturator ring not flush or below bourrelet diameter Cartridge assembly fails to fully traverse alignment gage Fuze not set on "s" (shipping position) Obturating ring damaged Inadequate torque on fin assembly Inadequate torque on fuze

100% 8/

Gage 2/

(4.5.3)

Gage 3/

Cartridge, 120mm:

SHEET 2 OF 3

ASSEMBLY

INSPECTION METHOD

Inadequate torque on ignition cartridge Obturator ring bond strength Outside diameter of body, max.

Ignition cartridge missing or not fully seated Fuze not fully seated Expelling charge assembly missing (prior to assembling fuze) Fin assembly not fully seated Obturator not free to rotate 5/ Orientation of expelling charge assembly improper 6/ Improper orientation of propelling charge increments Ignition cartridge cracked or damaged but not to the extent that propellant will escape

Thread locking compound improperly applied (applicable to the fuze, fin, and ignition cartridge - prior to assembly) Marking misleading or unidentifiable Evidence of poor

4.4.3.3

4/

3.6

3.9.1

4.5.6

Notes

4.4.2.18 Cartridge, 120MM:

SHEET 3 OF 3

ASSEMBLY

12577551

CRITERIA PARAGRAPH

INSPECTION METHOD

REFERENCE

PROVING GROUND TEST

Ballistic Testing 120 3.7 4.4.3.2/ (initial lot) 4.5.2 Ballistic testing 70 3.7 4.4.3.2/ (subsequent lot) 4.5.2

1/ This inspection shall be performed prior to assembling propelling charge supports to propelling charges.

2/ Gage used to detect for obturator not flush or below bourrelet diameter shall be used to detect for presence of obturator.

3/ See 4.5.7.

4/This inspection shall only be performed if touch-up painting is required in the bourrelet area.

5/ After bonding operation, the obturator shall be free to rotate.

6/ Expelling charge assembly shall be oriented in expulsion cup with cover side up (indentations in expelling charge assembly cover shall be visible).

7/ See paragraph 6.6.f.

8/ Inspection shall be performed prior to assembling ignition cartridge to fin housing.

4.4.2.19

Cartridge, 120mm, IR Illum M983 Loading Assembly (During

ASSEMBLY

INSPECTION METHOD

Parachute cup missing Expulsion cup missing Closure string not removed Suspension lines pulled out of parachute bag Baffle plate missing Expulsion plate missing O-ring missing O-ring not lubricated for a full 360 degrees or not lubricated Shell body surface not lubricated for a full 360 degrees or not lubricated Loading sleeve missing or not able to be separated (i.e. taped together) Spring pin ends (2) not flush with swivel pin after assembly Riser not able to rotate freely on spring pin after being assembled Swivel assembly not centered in riser cable coils Expulsion cup not fully seated Adhesive missing on expulsion cup Riser cable damaged during assembly

TITLE Cartridge, 120mm, IR

4.4.2.19 Illum M983 Loading

Assembly (During

SHEET 2 OF 2 12967863

117 Excessive amount of VL-IV 3.3 Visual riser cable protruding from parachute bag

118 Assembly force exceeded 1/ 3.3 Visual 119 Identification band 100% 3.3 Visual missing

120 Location of 100% 3.3 Visual identification band incorrect

Minor

Workmanship

1/ For each press used, the pressure shall be measured during First Article, at the beginning of each workday, every four (4) hours during production, and for the last component prior to, and the first component after each tooling or equipment change, repair, or adjustment.

4.4.2.20

Cartridge, 120mm: IR Illuminating M983 Loading Assembly (Final Assembly)

ASSEMBLY

INSPECTION METHOD

REFERENCE

Screw plug missing 4/

Location of shear pin holes from front/rear body interface Shear pins missing or loose Shear pin(s) not flush or below body 1/ Gap between front and rear bodies 2/ Depth of shear pin holes 3/ Number of shear pin holes 3/ Adhesive missing on screw plug (prior to assembly) Screw plug not flush or below body surface after assembly

Notes

CONFORMANCE INSOECTION

Cartridge, 120mm, IR

4.4.2.20 Illuminating M983

Loading Assembly (Final

SHEET 2 OF 2 12967863

EXAMINATION ON TEST

Conformance Criteria

REQUIREMENT PARAGRAGH

NEXT HIGHER ASSEMBLY

INSPECTION

METHOD REFERENCE

Minor

NOTES

1/ “Below flush” to be interpreted to mean below all surfaces of the shell body.

2/ The gap shall be measured for a full 360 degrees.

3/ In the event that a drill bit breaks or goes dull while drilling a hole, another hole may be drilled approximately 15 degrees from that hole. If a drill bit breaks in the hole, the broken drill bit shall be removed from the hole. All bare metal surfaces of the defective hole shall be touched up with paint, TT- E-516, Color No. 37875, FED-STD-595. No more than four additional holes shall be allowed (for a total of twelve holes). Through holes shall not be allowed.

4/ See paragraph 6.6.f.

Cartridge, 120mm: IR Illuminating M983

SHEET 1 OF 3

ASSEMBLY

INSPECTION METHOD

REFERENCE

Critical I

B

Obturator ring missing 7/

Fuze safety wire missing or not properly assembled 7/ Ignition cartridge cracked or damaged to the extent that propellant will escape 7/ Fin blade distorted 7/ Propelling charge increment(s) missing, cracked, or damaged to the extent that propellant will escape 1/7/

Delete Delete

Propelling charge increment(s) damaged but not to the extent that propellant will escape 1/ Obturator ring not flush or below bourrelet diameter Cartridge assembly fails to fully traverse alignment gage Fuze not set on "s" (shipping position) Obturating ring damaged Inadequate torque on fin assembly Inadequate torque on fuze

Gage 2/

Cartridge, 120mm: IR

SHEET 2 OF 3

ASSEMBLY

INSPECTION METHOD

Inadequate torque on ignition cartridge Obturator ring bond strength Outside diameter of body, max.

Ignition cartridge missing or not fully seated Fuze not fully seated Expelling charge assembly missing (prior to assembling fuze) Fin assembly not fully seated Identifying strip on fuze wire missing Obturator ring not free to rotate 5/ Orientation of expelling charge assembly improper 6/ Improper orientation of propelling charge increments Ignition cartridge cracked or damaged but not to the extent that propellant will escape

Thread locking compound improperly applied (applicable to the fuze, fin, and ignition cartridge - prior to assembly) Marking misleading or unidentifiable

4.4.3.3

4/

3.9.1

4.5.6

DRAWING NUMBER

4.4.2.21 Cartridge 120mm: IR

SHEET 3 OF 3 12967862

NEXT HIGHER

PROVING GROUND TEST

Ballistic testing 120 3.7 4.4.3.2/ (initial lot) 4.5.2 Ballistic testing 70 3.7 4.4.3.2/ (subsequent lot) 4.5.2

1/ This inspection shall be performed prior to assembling propelling charge supports to propelling charges.

2/ Gage used to detect for obturator not flush or below bourrelet diameter shall be used to detect for presence of obturator.

3/ See 4.5.7.

4/ This inspection shall only be performed if touch-up painting is required in the bourrelet area.

5/ After bonding operation, the obturator shall be free to rotate.

6/ Expelling charge assembly shall be oriented in expulsion cup with cover side up (indentations in expelling charge assembly cover shall be visible).

7/ See paragraph 6.6.f.

8/ Inspection shall be performed prior to assembling ignition cartridge to fin housing.

4.4.2.22

Container, Ammo, Fiber, PA153

12577509

ASSEMBLY

INSPECTION METHOD

Parts loose or not secured Container damaged

5.1

4.4.2.23

Packing & Marking for Container, Fiber, PA153 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, M983 (unsealed)

SHEET 1 OF 1 DRAWING NUMBER

12577551

NEXT HIGHER

ASSEMBLY

12577570

INSPECTION METHOD

REFERENCE

Propelling charge support missing or improperly positioned 1/

Fuze support missing (prior to insertion of cartridge) Cushion missing Fiber container parts not secure (prior to inserting cartridge)

Length of propelling charge support tab (min.)

NOTES: 1/ See paragraph 6.6.f.

Packing & Marking for Container, Fiber, PA153 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934, and M983 (sealed)

SHEET 1 OF 1 DRAWING NUMBER

12577551

NEXT HIGHER

ASSEMBLY

INSPECTION METHOD

Sealing strip incomplete, badly wrinkled or missing Contents loose Circular label missing from center of cap (applicable to M983) Marking missing, misleading, or

Length of sealing strip tab (min.)

4.4.2.25

Container, Metal, Shipping and Storage, Cartridge 120mm Mortar, PA154

SHEET 1 OF 1 DRAWING NUMBER

12577569

NEXT HIGHER

ASSEMBLY

INSPECTION METHOD

Parts loose or not secured

CONFORMANCE INSOECTION

4.4.2.26

Packing & Marking for Container, Metal, PA154 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934,M983 (unsealed)

SHEET 1 OF 1 DRAWING NUMBER

12577570

INSPECTION METHOD

Fiber container loose Containers improperly oriented Corrugated fiberboard damaged, missing, or improperly placed Plywood end plates damaged, missing, or improperly placed Pull strap damaged or missing

4.4.2.27

Packing & Marking for Container, Metal, PA154 for Cartridge, 120mm Mortar, M929, XM929, M930, M933, M934,M983 (sealed)

SHEET 1 OF 1 DRAWING NUMBER

12577570

INSPECTION METHOD

Contents of box loose Cover assembly not secure Security wires missing or broken Orange strip label missing at two locations (applicable to M983) Marking missing, misleading or

4.4.2.28

End Plate, Plywood

12577571

INSPECTION METHOD

Width Thickness Delamination One or more holes missing

VL-IV

5.1

Gage

4.4.2.29

Corrugate Fiberboard, Wide

12577573

INSPECTION METHOD

Delamination

4.4.2.30

Corrugate Fiberboard, Narrow

12577574

INSPECTION METHOD

Delamination

4.4.3 Testing.

4.4.3.1 Sampling plan for examination of location and

depth of shear pin holes. The location and depth of the shear pin holes shall be inspected in the following manner using approved gages. Beginning with the first production shift, ten

(10) consecutive drilled inert units shall be inspected and found defect free prior to rate production. Then inspect five

(5) units every two (2) hours until the end of the shift. Five

(5) units shall be inspected at the end of the shift. If a defect is found in any of the five (5) units, the machine set up shall be adjusted until ten (10) consecutive units are defect free. Production represented by the failed units shall be rejected and the machine set up shall be adjusted until ten (10) consecutive units are defect free.

4.4.3.2 Proving ground. The test shall be performed as

specified in 4.5.2. Defect classifications shall be in accordance with Table IV.

4.4.3.2.1 First article lot. A sample of 120 cartridges

shall be randomly selected for this test. Accept/reject criteria shall be as specified in 4.4.3.2.4.1.

4.4.3.2.2 Initial production lot. A sample of 120

cartridges shall be randomly selected for this test.

Accept/reject criteria shall be as specified in 4.4.3.2.4.1.

4.4.3.2.3 Subsequent production. After successfully

completing the initial production lot test, a sample of 70 cartridges shall be randomly selected for this test.

Accept/reject criteria shall be as specified in 4.4.3.2.4.2.

Table IV. Defect classifications

Category Defect Requirement Critical I Premature burst

Short round 3.7.2 3.7.4

Critical I Metal part failure 3.7.3 Major Misfire 3.7.1

Fuze non-function 3.7.5 Cartridge non-function 3.7.6.1 Illumination assembly fails to ignite or provide effective illumination (see Notes 1 and 2)

3.7.6.2 3.7.6.3

Fuze functioning time (see 6.6)

3.7.6.4

Note 1: If the fuze performance of any round in the sample does not meet the timing requirements specified and the round functions properly in all respects with the exception that the “effective illumination” time is less than the requirement because the illuminant and parachute assembly hit the ground while still burning, the illumination time defects shall not be additionally assessed against that round.

Note 2: If the fuze performance of any round in the sample meets the fuze functioning time (see 6.6) requirements, the mortar elevation (QE) is proper, the height of burst is above 500 meters (for the M930) and 600 meters (for the M983), and the “effective illumination” time is less than the requirement, the performance of the cartridge will be considered valid for evaluating the acceptability of the lot for illumination time defects. The following are considered some causes of this defect:

a. Delayed deployment of the parachute.

b. Streaming chute/ripped chute.

c. Partially or fully tangled chute.

d. Chute fails to deploy.

e. Illuminant detached from canister (illuminant dropout).

f. Parachute detached from canister.

4.4.3.2.4 Ballistic acceptance criteria.

4.4.3.2.4.1 Initial lot. The first article or initial lot

shall be rejected if:

a. One (1) or more premature bursts occur.

b. One (1) or more misfires occur.

c. One (1) or more short rounds occur.

d. Two (2) or more fuze non-functions occur (if a fuze functions on impact, it shall be considered a fuze non-function).

e. Two (2) or more non-separations of rear body from front body occur.

f. Fuze functioning time does not meet requirements (see 4.4.3.2.4.3).

g. Six or more functioning defects (see 6.6) occur (see Note 1).

Note 1: If one fuze non-function or non-separation of rear body from front body occurs, a maximum of five (5) additional defects are allowable for illumination less than 50 seconds in the air.

If one fuze non-function and one non-separation of rear body from front body occurs, a maximum of four (4) additional defects are allowable for illumination less than 50 seconds in the air.

If either two or more fuze non-functions or non-separations occur during testing, the First Article/initial lot shall be rejected.

4.4.3.2.4.2 Production. The lot shall be rejected if:

a. One (1) or more premature bursts occur.

b. One (1) or more misfires occur.

c. One (1) or more short rounds occur.

d. Two (2) or more fuze non-functions occur (if a fuze functions on impact, it shall be considered a fuze non-function).

e. Two (2) or more non-separations of rear body from front body occur.

f. Fuze functioning time does not meet requirements (see 4.4.3.2.4.3).

g. Four or more functioning defects (see 6.6) occur (see Note 1).

Note 1: If one fuze non-function or non-separation of rear body from front body occurs, a maximum of three (3) additional defects are allowable for illumination less than 50 seconds in the air. If one fuze non-function and one non-separation of rear body from front body occurs, a maximum of two (2) additional defects for illumination less than 50 seconds are allowable. If either two or more fuze non-functions or non-separations occur during testing, the lot shall be rejected.

4.4.3.2.4.3 Acceptance criteria for fuze.

4.4.3.2.4.3.1 The lot shall be rejected if an individual

fuze function time fails to fall within the upper and lower limits for the 21 degree Celsius test groups.

4.4.3.3 Strength of obturator bond. For First Article and

production, a minimum of five (5) and ten (10) obturating rings, respectively, per welder, shall be selected from each day’s production, assembled to a test fixture, introduced to the production line, bonded, and tested as specified in 4.5.6. The bonding process shall not leave any residue or excess material (flash), or bond to the shell body. The obturator band shall not fail at any point before reaching the required load (the bonded joint may be stronger than other parts of the ring (e.g. slit)).

Failure of the sample to meet the requirement shall be cause for those cartridges represented by the sample to be rebanded and retested.

4.5 Methods of inspection.

4.5.1 Materials components and processes. Compliance with

all requirements of Section 3 of this specification shall be ascertained by current and continuing examination of inspection and test results to determine that all components (parts, subassemblies and materials) have been inspected and tested and found to comply with their respective drawings and specification requirements, and that all specified manufacturing processes have been followed.

4.5.1.1 Visual and mechanical inspection. The visual, manual, and mechanical inspections and tests verify compliance with the requirements of Sections 3 and 5 of this specification in accordance with 4.4.2 herein and Table III.

4.5.2 Proving ground testing. The cartridges for first

article testing and the first production lot acceptance shall be separated into three groups: one group of 24 conditioned at 49 ± 1oC for 24 hours, one group of 72 conditioned at 21 ± 1oC for 24 hours, and one group of 24 conditioned to -32 ± 1oC for 24 hours.

The quantities shall be tested at charges as indicated in Table V.

The cartridges for subsequent production lot acceptance shall be separated into three groups: one group of 14 conditioned at 49 ± 1oC for 24 hours, one group of 42 conditioned at 21 ± 1oC for 24 hours, and one group of 14 rounds conditioned at -32 ± 1oC for 24 hours. The quantities shall be tested at charges as indicated in Table V.

TABLE V: Proving ground tests

49 ± 1oC 21 ± 1oC -32 ± 1oC

CHARGE

NUMBER

FIRST

ARTICLE/

FIRST

LOT

PROD

LAT

FIRST

ARTICLE/

FIRST

LOT

PROD

LAT

FIRST

ARTICLE/

FIRST

LOT

PROD

LAT

4 12 7 36 21 12 7 1 12 7 36 21 12 7

Fuze settings and weapon elevation shall be as specified in Table VI. If meteorological conditions or time of fuze func-tioning so dictate, the proving ground shall adjust the fuze setting to change the burst height to insure effective illumination.

TABLE VI: Test settings

Round Type

Charge Temperature (oC)

Fuze Setting (sec)

Mortar Elevation (mils)

Height of Burst

(meters) M930 1 -32 18 899 500-600

4 -32 40 899 500-600 1 21 19 899 500-600 4 21 42 899 500-600 1 49 21 899 500-600 4 49 43 899 500-600

M983 1 -32 16 899 600-700 4 -32 39 899 600-700 1 21 18 899 600-700 4 21 41 899 600-700 1 49 20 899 600-700 4 49 42 899 600-700

The cartridges shall be fired from a 120mm M121 carrier mounted mortar. The mortar tube shall be dry swabbed every five rounds at zone 1, and every ten rounds at zone 4 counting seater, warmer, spotter, test, and reference rounds. The individual cartridge weights, velocities, pressures, range at fuze function, time of fuze functioning, height of burst (HOB), and illuminant burn time shall be measured. Photographs of each fuze setting shall be taken to verify the setting and that the safety pull wire has been removed. Observation shall be made for misfires, premature burst, security of metal parts, fuze functioning, cartridge deployment, and “effective” illumination (see 6.6). A smear camera or equivalent shall be used to photograph all test samples. Should an unobserved dud, short round, or any other abnormal performance occur, a photo print of those rounds and prints of all other rounds in that test group shall be available for review.

Weibel radar or equivalent shall be used to observe for metal parts separation, unobserved short rounds, and unobserved duds. In these events, an analysis should be made of the radar data. This shall include a comparison of flights of the unobserved rounds with those of the normal rounds. Prints of the radar traces of these rounds and prints of the preceding and succeeding rounds shall be available.

4.5.2.1 Test validity. If for any reason the proving

ground personnel consider that the test conditions have detrimentally affected the test results, the test result shall be declared invalid and a new test shall be performed on additional sample cartridges.

4.5.3 Damaged propelling charge. To ascertain whether a

damaged propelling charge is to be classed as critical or major, the following procedure shall be used:

a. Place the damaged charge on a M31 fin, oriented such that the propellant would be resting against the damaged surface.

b. The fin charge shall be hand-shaken vigorously three times.

c. Examination shall be made for propellant spillage. If any propellant is observed, the damaged propelling charge shall be classed as a critical defect. If no propellant is observed, the damaged propelling charge shall be classed as a major defect.

4.5.4 Leak test. For First Article, five expelling

charge assemblies shall be subjected to a leak test. For production, a minimum of five expelling charge assemblies shall be randomly selected after each four hours of production and subjected to a leak test.

The sealed expelling charge assembly shall be subjected to a pressure of 3 +/- 1 psig for a duration of five (5) seconds.

There shall be no leakage. Any expelling charge assembly which leaks shall be rejected and removed from the lot. The production represented by the sample shall be rejected.

Rejected parts shall be subjected to 100% leak test inspection and those passing shall be placed into acceptable status.

All equipment used in this test shall be capable of performing the test accurately and consistently. Equipment shall be calibrated at the start of each shift and thereafter, at intervals of not more than four (4) hours of continuous operation. It shall also be calibrated prior to restarting the operation after a layoff of three (3) hours or more. If it is found that the equipment is out of calibration, the expelling charge assemblies tested since the last satisfactory calibration shall be retested after the equipment has been corrected.

4.5.5 Moisture content of black powder. The moisture

content of the black powder shall be determined in accordance with the procedure specified in MIL-P-223. The samples shall be randomly selected from each four hours production. Any failure to comply with the applicable requirement shall be cause for rejection of the four hours production represented by the sample. If loading has begun, expelling charge assemblies loaded with the nonconforming black powder shall be rejected.

4.5.6 Strength of bonded obturator. The sample shall be

oriented on the test fixture such that the bonded joint is 180 degrees away from the point at which the test load will be applied. The load will then be applied in a radial direction away from the axis (center) of the ring until failure occurs.

4.5.7 Torque test. The samples supplied in accordance

with 4.4.2.15, 4.4.2.17, 4.4.2.18, and 4.4.2.20 shall be tested by applying the required torque to the components in the direction of assembly before the thread sealing compound has set. Any perceptible movement of parts will be considered as failure of the assembly to comply with the requirement.

4.5.8 Obturator inspection. All assembled and bonded

obturators shall be visually and manually inspected to verify that they are properly bonded and free to rotate.

4.5.9 Check test for possible deterioration of ignition

cartridge. A sample of 35 ignition cartridges shall be subjected to a velocity, functioning, and security ballistic test. If the mean velocity or velocity standard deviation exceeds the requirements specified in 3.7.3 of DTL12977364, the lot shall be rejected. If any round fails to function for reasons attributable to ignition cartridge failure, or if a metal parts separation occurs, the lot shall be referred. The test shall be performed as specified in 4.5.5 of DTL12977364.

5. PACKAGING

5.1 Packaging. For acquisition purposes the packaging

requirements shall be as specified in the contract or order (see 6.2). When actual packaging of material is to be performed by DOD personnel, these personnel need to contact the responsible packaging activity to ascertain requisite packaging requirements. Packaging requirements are maintained by the Inventory Control Point’s packaging activity within the Military Department or Defense Agency, or within the Military Department’s System Command. Packaging data retrieval is available from the managing Military Department’s or Defense Agency’s automated packaging files, CD-ROM products, or by contacting the responsible packaging activity.

6. NOTES

(This section contains information of a general or explanatory nature that may be helpful but is not mandatory.)

6.1 Intended use. The components covered by this

specification are intended for use with the M930 and M983 120mm Illuminating/IR Cartridges. The components covered by this specification are military unique because they are fired from 120mm mortars and have no commercial application.

6.2 Acquisition requirements. Acquisition documents must

specify the following:

a. Title number and date of this specification.

b. Issue of DODISS to be cited in the solicitation and if required, the specific issue of individual documents referenced (see 2.1.1).

c. Packaging requirements (see 5.1).

d. Requirements for First Article (see 4.3)

e. Requirements for acceptance inspection equipment (AIE) designs (see 6.3)

f. Certification of conformance requirement for each lot or shipment of product.

6.3 Submission of contractor inspection equipment designs

for approval. Submit copies of designs as required to:

Commander, U S Army ARDEC, ATTN: AMSTA-AR-QAA-C, Picatinny Arsenal NJ 07806—5000.

6.4 Drawings. Drawings listed in Section 2 of this

specification under the heading U.S. Army Armament Research Development and Engineering Center (ARDEC) may also include drawings prepared by U.S. Army Armament, Research and Development Command (ARRADCOM), Frankford Arsenal, Rock Island Arsenal or Picatinny Arsenal drawings. Technical data originally prepared by these activities is now under cognizance of ARDEC.

6.5 Submission of alternative conformance provisions. All

contractor proposed alternative conformance provisions will be submitted to the Government for evaluation/approval as directed by the contracting activity.

6.6 Definitions. The following definitions are provided:

a. Effective illumination. Effective illumination is defined as burning of the canister without exploding or breaking up while suspended by the parachute. The time recorded for "effective illumination" shall be considered as the time from the appearance of the first light from the candle to either (1) burnout of the candle while still in the air or (2) burning of the candle until ground impact. Burning of the canister after striking the ground shall not be considered as "effective illumination".

b. Verification methods:

Analysis. Use of analytical methods and mathematical formulas to determine if an item meets a requirement.

Demonstration. A functional test (for example, ballistic firing) that provides verification that a requirement is met.

Examination. Inspections utilizing gaging or visual means to assure conformance to a requirement.

Test. The conduct of specific procedures and methods to provide data verifying a requirement is met.

c. Fuze functioning time. The elapsed time from round initiation in the mortar tube to first flash as fuze ejects the payload.

d. Functioning defect. An illuminant assembly which fails to ignite or provide effective illumination.

e. Critical II defect. A Critical II defect is a defect, other than Critical I, that judgment and experience indicate may, depending on the degree of variance from the design requirement:

1) Result in hazardous or unsafe conditions for

Individuals using, maintaining or relying upon the product; or

2) Prevent performance of the tactical function of a major end item.

f. Critical Classification Rationale:

Paragraph Critical Callouts

Critical Rationale

4.4.2.17/4.4.2.20 Critical I 1 Screw plug missing

The absence of a screw plug will allow propellant gases to enter the cartridge and pressurize the cartridge, resulting in separation of the front and rear shell bodies. Serious injury to the gun crew is likely.

4.4.2.18/4.4.2.21 Critical I 2 Obturator ring missing

The obturator ring creates a pressure seal providing consistent muzzle velocity and angle of attack. Defect will allow propulsion pressure to blow by, likely creating a short round or off target round. A decrease in chamber pressure will decrease the muzzle velocity of the cartridge, reducing the horizontal range.

A short round can function in the proximity of friendly troops, likely resulting in death or serious injury to the soldier.

Critical I 3 Fuze safety wire missing or not properly assembled

The fuze safety wire is a safety feature of the M776 fuze used on the M930 and M983 cartridges. The fuze safety wire mechanically prevents the fuze explosive train from reaching an armed position.

The shock generated from a drop may result in the initiation of the…