Attachment 03_SCATP 9mm.pdf

SCATP-9mm

18 February 2010

DEPARTMENT OF DEFENSE

SMALL CALIBER AMMUNITION TEST PROCEDURES

9MM CARTRIDGES

FSC 1305

DEPARTMENT OF DEFENSE

ii

Washington, DC 20301

Small Caliber Ammunition Test Procedures, 9mm Cartridges

1. This Military Standard is approved for use by the US Army Armament Research, Development and Engineering Center and is available for use by all Departments and Agencies of the Department of Defense.

2. Recommended changes should be addressed to:

US Army Armament Research, Development and Engineering Center

ATTN: AMSTA-AR-QAC-C

Dover, New Jersey 07806-5000 iii

FOREWORD

PURPOSE

The purpose of this publication is to prescribe uniform proof and inspection procedures to be used by all proof-testing facilities for acceptance inspection of 9mm ammunition. Adherence to these procedures, and equipment listed in the Inspection Equipment List, is considered necessary to assure uniformity of test results; however, if conflicts are encountered between the provisions of this pamphlet and the item specification, the latter will apply.

NUMBERING SYSTEM

Each section carries its own independent sequence of page and paragraph numbers. Pages are numbered as follows: The figure preceding the dash represents the number of the section and the number following the dash denotes the page within the section. Thus, 2-4 means section 2, page 4.

INSPECTION EQUIPMENT LISTS

Inspection Equipment Lists contain a complete list of the equipment, together with the drawing numbers of the equipment that shall be used for the individual tests. Each specification identifies the appropriate Inspection Equipment List.

RECORDING OF DATA

The suggested format contained at the end of each test procedure may be used for recording test data. The data recorded shall be as prescribed by the various sections of this pamphlet and as prescribed by the item specification.

SAFETY

It must be recognized and emphasized that all proof-testing is hazardous. During the conduct of any test or operation described in this regulation, all local installation safety precautions and rules shall be observed.

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CONTENTS

1. Weapon Unit Guide

2. Reference Cartridges

3. Accuracy Test Procedures

4. Electronic Pressure, velocity and Action

Time (EPVAT) Procedure

5. Bullet Extraction

6. Function and Casualty Test Procedure

7. Mercurous Nitrate Test Procedure

8. Waterproof Test Procedure

Procedure I (Firing Test)

Procedure II (Vacuum Test)

9. Primer Sensitivity Test Procedure

10. Compressive Force Test Procedure

11. Oil Resistance Test Procedure

12. Mid-Case Chamber Pressure Test Procedure

Appendix A. Piezoelectric Pressure Transducer, Electronic Instrumentation Requirements

Appendix B. Piezoelectric Pressure Transducer, Electronic Instrumentation Calibration

Procedures

Appendix C. Pressure Transducer Qualification Test

Appendix D. Ballistic Transducer Installation and Operation Procedure

Appendix E. Ballistic Pressure Transducer Sensitivity Determination

1-1

SECTION 1

WEAPON UNIT GUIDE

1. PURPOSE

The inspection, maintenance and cleaning of ballistic equipment is an important part of proof technique. Weapons used for official acceptance tests shall be inspected, maintained and cleaned in accordance with the practices outlined herein. Complete records of the wear history of weapons should be maintained for reference as a possible aid in the interpretation of ballistic results. All weapons shall be controlled by regular inspection and maintenance.

2. EQUIPMENT

Equipment listed in the applicable Inspection Equipment List shall be used.

3. FIRING-PIN MEASUREMENTS

3.1 Before comparability in test conditions can be established between stations, it is necessary that attention be paid to firing-pin diameter and contour, firing-pin protrusion and firing-pin indent of the test weapons and test actions. These measurements shall be made before a weapon or test action is placed in service, after misfires, pierced primers or flowbacks; or whenever a part replacement has been made in the bolt assembly.

3.1.1 Firing-pin diameter shall be checked with a micrometer, however, when difficulty is experienced with an unusual series of primer defects, the contour of the firing-pin point should be checked with a templet or visual comparator. The diameter of the firing-pin hole in the face plate should be checked concurrently. A loose fit between firing-pin and firing-pin hole, due to improper diameter of either or both, may cause punchouts of the primer and loss of sensitivity due to eccentric blow.

3.1.2 Firing-pin protrusion must be checked frequently to insure against pierced primers or misfires. Pin protrusion is measured with a dial gage of such construction as to be suitable for the particular weapon or action involved.

3.1.3 Firing-pin indent shall be measured by placing a copper pressure cylinder in a fixture

(drawings of cylinder and fixture are referenced in the applicable Inspection Equipment List), the fixture is then inserted in the chamber of the weapon, the bolt is closed and the firing-pin released. The cylinder is then removed and the distance from the bottom of the indent to the undeformed surface of the cylinder is measured using a dial gage. A point micrometer graduated to .001", may also be used. This measurement is subtracted from the original measurement, the difference shall be the primer indent measurement.

(NOTE: Firing-pin indent and firing-pin protrusion shall be as shown in the detailed sections of this regulation.)

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4. MEASUREMENT OF GUN CHARACTERISTICS

4.1 Headspace. The headspace of all test and service weapons shall be measured the first time they are put in use, during any shift or when fitting new barrels to fixed receivers. All test and service weapons shall conform to the headspace tolerance specified in the detailed sections of this regulation.

4.2 The headspace measurement for weapons containing the M1903 receiver is made as follows:

4.2.1 The bolt is stripped so that the operator will not be deceived by the drag caused by the extractor or other parts. A headspace gage is then selected by trial and error, which, when inserted into the chamber like a cartridge, will just allow the bolt to close when moderate pressure is applied. The dimension of this gage is the value of the headspace of the weapon. This measurement is checked by removing this headspace gage from the chamber, and inserting the next larger gage (plus .001") which should stop the bolt before it is completely closed.

4.2.2 Corrections to headspace shall be made by the gunsmith only.

5. CARE AND MAINTENANCE OF WEAPONS

Proper cleaning and lubricating of all ballistic equipment is essential for accurate reproducible proof results.

5.1 The bore of the weapon is cleaned as follows:

5.1.1 A soft bristle brush is saturated with cleaner and worked through the barrel with a vigorous scrubbing action. A brass brush is then run completely through the barrel in one long continuous stroke. When the brush emerges from the opposite end of the barrel the stroke is reversed and the brush is withdrawn through the barrel.

5.1.2 The bore is again swabbed with a soft bristle brush soaked in solvent. A cloth

'patch soaked in solvent is run through the bore several times. The chamber is carefully wiped with a similar patch.

5.1.3 A succession of clean cloth patches is then run through the bore until it is completely dry and clean. If barrel is not to be used in the immediate future, a clean patch is immersed in oil and run through the barrel so that a light film covers the chamber and bore.

5.1.4 Whenever the construction of the gun permits it, the bore is cleaned from the breech.

When it is necessary to clean from the muzzle, special care is necessary in cleaning the chamber in order to remove the dirt, lint and bristles deposited therein during cleaning of the bore.

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5.2 Small metal parts are cleaned by immersing in a bath of solvent or cleaner and scrubbing vigorously with a brass brush. Large metal parts are cleaned by wiping with a cloth soaked in solvent, cleaner or light oil.

5.3 Frequency of lubricating and cleaning.

5.3.1 Special test weapons (Receivers, Pressure Gages, etc.).

5.3.1.1 The bore and chamber are cleaned and lightly oiled at the close of each shift in which the weapon is used. All exposed parts of the receiver are wiped with an oily cloth.

5.3.1.2 Once each week, each test action in current use is completely dismantled, inspected, cleaned and lubricated.

5.3.1.3 Metal fouling is removed when it becomes too thick. The time for removal of such fouling is left to the judgment of the gunsmith, but the barrel is never allowed to foul to the point where the fouling begins to scale off.

5.3.2 Service weapons.

5.3.2.1 The chamber and bore are cleaned at the close of firing on each shift in which the weapon is used.

5.3.2.2 The receiver and bolt groups of each weapon are completely disassembled and cleaned at the close of firing on each shift or after 500 cartridges have been fired, if more than

500 cartridges be fired per shift. The hammer and trigger groups of automatic weapons are completely disassembled and cleaned as needed. Complete disassembly of the trigger and hammer groups each day is unnecessary.

5.3.2.3 The weapon is lubricated after each cleaning. Lubrication is applied to all moving parts and to the bore.

5.4 Inspection of weapons.

5.4.1 All of the items listed are checked in the initial inspection of the weapon; items marked (*) are checked daily; and items marked (**) are checked weekly when a weapon is used frequently or continuously.

a. Universal Receivers and assemblies containing the M1903 Receiver.

(1) Unpack, remove rust preventive

* (2) Disassemble, clean and lubricate

* (3) Inspect chamber and bore

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(4) Check headspace

(5) Check bullet seat (breechbore gage)

(6) Examine camming and locking mechanisms

(7) Examine striker and bolt

** (8) Check firing-pin protrusion

** (9) Check firing-pin indent

* (10) Hand function, to check smoothness of feeding and ejection

b. Sub-machine guns

* (4) Examine firing-pin and bolt

* (5) Check firing-pin protrusion

* (6) Check headspace

** (7) Check firing-pin indent (where applicable)

* (8) Assemble and function with dummy ammunition

c. Pistols

* (4) Examine receiver and slide

* (5) Test action with dummy ammunition

1-5

6. REMOVAL OF METAL FOULING

6.1 The solution used for the removal of metal fouling consists of the following:

Ammonium per sulphate, USP . . . . . . . . . 1 oz.

Ammonium carbonate, USP . . . . . . . . . 0.5 oz.

Ammonia water (28% NH3 oz. vol.)

Spec. O-A-451, Class B . . . . . . . . . . . 6 oz.

Water . . . . . . . . . . . . . . . . . . . 4 oz.

It is recommended that this solution be prepared as required.

NOTE: This solution is very corrosive when allowed to dry on a metal surface or if brought in contact with a hot surface of a barrel. Great care should be exercised to see that it does not come in contact with blued metal or with gun actions.

6.2 To remove metal fouling, the barrel should be thoroughly cleaned. To remove the last traces of oil, a single cartridge should fired through it just before introduction of the fouling solution.

6.3 A tight fitting stopper is inserted into the bullet seat, and the fouling solution poured into the barrel until it is filled completely up to the muzzle.

6.4 If the solution does not completely fill the barrel, a line of corrosion will be formed.

Some method must therefore be used to assure the barrel remains completely full. (A rubber tube slipped over the muzzle, a crater of grease built up around the muzzle, or the constant observation and addition of solution as it evaporates.)

6.5 After one-half hour, the solution is poured out and the color noted. If the color is a deep blue, the treatment must be repeated. Between each application and after the final one (when the solution shows only a light trace of blue) the barrel is washed out with hot water, then cleaned with a wire brush and dried with cloth patches.

2-1

SECTION 2

REFERENCE CARTRIDGES

1.1 The reference cartridges shall be used to establish the ballistic and equipment corrections for: Qualification Approval, Production Acceptance, and Surveillance Tests. In addition, the cartridges may be used to determine barrel serviceability or to check on other equipment or ballistic measurements. The reference lot will meet all the requirements of this manual and STANAG 4090.

1.2 NATO requirements. The Regional Test Center will maintain and supply Cartridge, Reference, NATO. The Test Center will fire an assessment and publish the following values for the reference cartridge:

a. Ballistic Data (EPVAT):

Average Velocity Results at 16 meters

Extreme Variation

Standard Deviation

Average Casemouth Pressure Results

Extreme Variation

Standard Deviation

Average Action Time Results at 21 degrees C

b. Assessment values:

Velocity at 16 meters

Case Mouth Pressure

Action Time at 21 degrees C

1.3 Review of assessed values. The superintendents of the Regional Test Centers will monitor the assessed values of the reference lot in the following manner:

a. The data from all firings of the reference cartridges conducted at the Regional

Test Centers during a calendar year will be maintained.

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b. Charts will be prepared showing the average values obtained at each of the

Regional Test Centers and the combined averages. These will be plotted against the assessed values and the difference obtained. Significant differences will be statistically determined by using an "f" or "t" test.

2.1 Required equipment is listed.

a. Reference cartridges

b. EPVAT barrels

c. Piezoelectric gages (Kistler Model 6215)

d. Associated recording instrumentation

3. PREPARATION

3.1 Cartridge storage area. Upon receipt of reference cartridges, the cartridges shall be placed in a dry storage area. Extreme variations in temperature within the storage area shall be held to a minimum.

3.2 Cartridge conditioning. Upon removal from the storage area, reference cartridges shall be conditioned at a constant temperature of approximately 21 degrees C for a minimum of 24 hours prior to being placed in the constant temperature controlled box for 2 hours at 21 degrees

C, + 2 degrees C.

3.3 Master assessment barrels. The five EPVAT barrels used for the official assessment of the reference lot shall be defined as the "master assessment" barrels and shall be retained for use in assessing a new reference lot or reassessing the original lot if its values are significantly changing.

4. CONDUCTING THE TEST

4.1 Conducting assessment. The manner and sequence for conducting the assessment shall be the same as described in the EPVAT Test, SECTION 4, using EPVAT test barrels previously fired approximately 500 times. Twenty cartridges shall be fired in each of five EPVAT barrel pressure gage assemblies. The average velocity at 16 meters, case mouth pressures, and action item with the five EPVAT barrel pressure gage assemblies for the first day shall be obtained. If the average velocity of any barrel assembly deviates from the average of the five barrels by more than 6 meters per second or if the standard deviation for any individual barrel exceeds 10 meters per second, that barrel shall be replaced with another barrel and the firing for that barrel repeated and new averages calculated. An additional 20 cartridges shall be fired in the same manner in the same five EPVAT test barrels and with the same pressure gages on each of the 2 succeeding

2-3 days. The velocity difference between the highest and lowest daily averages should not exceed 4 meters per second.

4.2 Simulated assessment. A simulated assessment test will be conducted at the discretion of the National Test Agencies or at the request of the Regional Test Centers. The purpose of a simulated assessment test is to provide a comparison between the various test centers for verification/correlation of test procedures, equipment used, and data obtained.

4.2.1 Procedure for conducting simulated assessment. The procedures are the same as previously described; however, the test barrels used will not be the "master assessed" barrels but a group of five barrels selected by the National Test Center or the Regional Test Center. The

500-round "life" for these barrels can be obtained by firing NATO qualified cartridges of the same type as the reference lot. The simulated assessment will first be conducted at the National

Test Center and the results reported to the Regional Test Center. If the results are significantly different from the official assessed values for the reference lot, the barrels will be supplied to the

Regional Test Center which will repeat the simulated assessment test.

5. RECORDING OF RESULTS

5.1 Upon completion of the tests, the average velocity, case mouth pressure and action time, for the entire series shall be computed.

5.2 Sentencing.

5.2.1 Official assessed values. The Regional Test Center superintendent will publish, as a

NATO document, the official assessed values for the reference lot.

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SECTION 3

ACCURACY TEST PROCEDURE

1.1 The Accuracy Test is fired under controlled conditions at a target located at a specified distance from the weapon to determine the uniformity and dispersion of bullets. In order to minimize weapon inaccuracies, the test shall be fired in a rigidly mounted test weapon.

2.1 Equipment listed in the Accuracy Section of the appropriate Inspection Equipment List shall be used.

2.2 The target size for Accuracy Tests shall not be less than 600mm x 600mm. A windup motor operated by remote control may be used for changing to a new target.

2.3 The pier or mount, on which the test assembly is mounted, shall be of solid construction.

3.1 The flight of the bullet is affected to a degree by the direction and velocity of the wind over the outdoor range. Therefore, accuracy tests should not be fired when the velocity of the transverse wind is greater than 16km per hour (10 mph), or varying by more than 8km per hour

(5 mph).

3.2 The following measurements shall be made before a test weapon is placed in service, after misfires, pierced primers or flowbacks; or whenever a part replacement has been made in the assembly:

Limits

Firing-pin protrusion 1.52 - 1.73mm

Firing-pin indent 0.28 - 0.38mm

Headspace 19.15 - 19.23mm

3.3 The accuracy test weapon is assembled and clamped in position on the mount and boresighted into position. It is of prime importance that the assembly be mounted properly so that the weapon maintains its original position from shot to shot.

3.4 The test cartridges shall be placed at a point convenient to the technician. It is not necessary to condition the ammunition at a specified temperature, prior to firing. However, it is necessary that all cartridges be uniform with respect to temperature.

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3.5 Two weapons shall be used. The number of targets to be fired shall be divided equally among the number of weapons to be used.

4.1 A sufficient number of unrecorded cartridges of the type of ammunition under test shall be fired to assure that the test weapon is correctly sighted on the target, but in any event a minimum of three cartridges shall be fired to warm and foul the weapon when it is first put into service and after it has been cleaned or cooled. The approximate location of the shots fired is reported to the technician in order that alignment of the weapon may be adjusted, if necessary.

4.2 After the warming (fouling) cartridges have been fired, the target shall be changed so as to present a fresh surface for the succeeding target. Thereafter, the target shall be changed after each target of 10 cartridges has been fired.

4.3 Consideration is not given to the position of the propellant in the cartridge case, except that the manner of handling the ammunition from cartridge to cartridge is reasonably uniform.

Ten cartridges shall then be fired in even sequence at a rhythmic uniform rate, as rapidly as service of the weapon permits.

4.4 The approximate location of the center of impact and the estimated size (Extreme

Vertical and Extreme Horizontal) of the target first fired shall be reported to the technician by the observer in the target area, in order that alignment of the weapon may be adjusted if necessary.

4.5 The procedure shall be repeated until the specified number of targets has been fired in the first weapon, or when the exposed metal surface of the test barrel becomes too hot to grasp with the bare hand (approximately 60ºC), at which time the barrel shall be cooled to ambient temperature before the next target is fired.

4.6 After the required number of targets has been fired with the first weapon, that weapon shall be removed from the mount and cooled to ambient temperature.

4.7 The second test weapon shall then be assembled on the mount and the procedure prescribed in 4.1 through 4.5 is repeated.

4.8 If it is necessary to use a weapon after it has been cooled with water, the chamber and bore of the weapon shall be wiped dry before any additional firing, and three warming (fouling) cartridges shall be fired.

5. MEASUREMENT OF TARGET

5.1 Explanation of terms.

5.1.1 Extreme Vertical (Ex. Ver.). Vertical distance between the center of the hole made by the uppermost shot and the center of the hole made by the lowermost shot.

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5.1.2 Extreme Horizontal (Ex. Hor.). Horizontal distance between the center of the hole made by the shot farthest to the right and the center of the hole made by the shot farthest to the left.

5.1.3 Extreme Spread (Ex. Spr.). Distance between centers of the shot holes farthest apart.

5.1.4 Mean Radius (M.R.). Arithmetic mean of the distances between the center of all shot holes and a point of the target called the Center of Impact.

5.1.5 Center of Impact (C.I.). Defined as the point at which the algebraic sums of the vertical and horizontal components respectively of the distances to the center of each shot hole are zero.

5.2 Targets shall be measured and Mean Radius of each target determined in the manner indicated and illustrated on Drawings I and II at the end of this section.

5.3 Draw a horizontal line, PA through the center of the lowest shot hole on the target and extend it horizontally in both directions until its length is equal to or greater than the width of the group of shots comprising the target.

5.4 Draw a vertical line, PB through the center of the shot hole on the extreme left of the target perpendicular to the meeting line PA at P. Extend line PB above PA until the length of PB is equal to or greater than the height of the group of shots comprising the target.

5.5 Measure (by means of the scale or opisometer) the perpendicular distance Y from the center of each shot hole on the target to line PA. Add the distance so obtained and divide by the number of shots. The result of this calculation is the average vertical distance of the shot holes above the baseline PA, and is designated by Y. Similarly, measure (by means of the scale or opisometer) the perpendicular distance X from the center of each shot hole to line PB, add the distances so obtained and divide by the number of shots. The result is the average horizontal distance of the shot holes from the vertical ordinate PB, and is designated X.

5.6 Location of Center of Impact. From P, measure along PB a distance, PD, equal to Y, and along PA measure a distance, PE, equal to X. At points E and D erect the respective perpendiculars EC and DC to lines PA and PB. The intersection of these perpendiculars is the

Center of Impact of the target, C. See Drawing I at the end of this section.

5.7 Mean Radius (M.R.). From the Center of Impact, measure the distance to the center of each shot hole of the target. Add these distances and divide by the number of shot holes. The result is the M.R. Drawing II at the end of this section illustrates the procedures.

5.8 If one or more shots miss the target in any 10 shot series, the entire accuracy test shall be considered invalid and refired at a larger target, as necessary to insure hits.

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6. RECORDING OF RESULTS

6.1 All dimensions of the group shall be recorded to the nearest millimeter. Test sheets shall show the following:

a. Mean Radius

b. Extreme Horizontal

c. Extreme Vertical

d. Extreme Spread

e. Velocity and direction of wind (outdoor range)

f. Number and type of case casualties

g. Misfires

The following test weapon data shall be recorded on the test sheet:

a. Receiver number

b. Barrel number

c. Total number of cartridges fired in barrel (prior to test)

d. Headspace measurement

7. FACTORS AFFECTING ACCURACY TESTS

7.1 The external factors should be controlled as closely as possible in order to obtain results that are representative of the inherent accuracy of the ammunition.

7.2 The dimensions and condition of accuracy weapons, as well as the manner of placing the weapon in the rest, are of prime Importance.

7.3 The technique of test can affect accuracy results. if uniformity in the manner in which the cartridges are handled, chambered and fired be poor, a larger Mean Radius is obtained than if the cartridges be tested in a uniform manner.

7.4 The temperature of the test barrel should be controlled so that the exposed metal surface of the barrel does not become too hot to grasp with the bare hands (approximately 60ºC), at which time the weapon shall be cooled to ambient temperature before the next target is fired.

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N

Z M.R.

X

E

D

Y

P

C

B

A

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

E

X

X

X

X

X

X

X

X

X

X

YY Y Y YYYYYY

1 2 3 4 5 6 7 8 9 10

D

Y

P X

C

B

A

Y = = PD

Y

N

X = N

= PE

X

DRAWING I

DRAWING II

N

Z M.R.

X

E

D

Y

P

C

B

A

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

N

Z M.R.=

N

Z M.R.

X

E

D

Y

P

C

B

A

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

XX

E

D

YY

P

C

B

A

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

Z

E

X

X

X

X

X

X

X

X

X

X

YY Y Y YYYYYY

1 2 3 4 5 6 7 8 9 10

D

Y

P X

C

B

A

Y = = PD

Y

N

X = N

= PE

X

E

X

X

X

X

X

X

X

X

X

X

YY Y Y YYYYYY

1 2 3 4 5 6 7 8 9 10

D

Y

P X

C

B

A

E

X

X

X

X

X

X

X

X

X

X

YY Y Y YYYYYY

1 2 3 4 5 6 7 8 9 10

D

YY

P XX

C

B

A

Y = = PD

Y

N

X = N

= PE

X

YY = = PD

Y

N

XX =

N

= PE

X

DRAWING I

DRAWING II

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Propellant: Engineering Proof Testing Record

Accuracy Test at Yds

Ammunition:

Type Lot

Army Lot Type

Charge Caliber

Case Bullet

Primer Wt.

Gun Receiver Barrel Times

Fired

Headspace Pin

Protrusion

Avg. MR Wind

MPH Dir.

Gun

No.

Target

No.

Mean

Radius

Ex. Ver. Ex. Hor. Ex. Spread

Remarks:

Proof Technician(s)

Date Fired

4-1

SECTION 4

ELECTRONIC PRESSURE, VELOCITY

AND ACTION TIME (EPVAT) TEST PROCEDURE

1.1 The testing of ammunition for velocity, action time, and peak pressure at the case mouth shall be done simultaneously using a piezoelectric pressure transducer and associated equipment to measure the case mouth pressure. The purpose of testing for these attributes is as follows:

a. Velocity: The velocity test is a precisely controlled test to ascertain the velocity uniformity and level of the ammunition lot under test and to determine if the average velocity and uniformity obtained complies with the requirements of the applicable specification.

b. Action time: Action time is the overall ignition, propellant burning and barrel time of a bullet. The test serves to establish the performance level of the ammunition by recording the individual performance of each cartridge with respect to each other, as well as with respect to the entire group.

c. Case mouth pressure: The case mouth pressure test determines the pressure exerted, expressed in megapascals (MPa) in the chamber of the gun. The test is performed as a safety measure to insure that the pressure developed by the ammunition is safe for firing in the weapon(s) for which it is intended.

2.1 Equipment listed in the Electronic Pressure Velocity, and Action Time (EPVAT) section of the appropriate Inspection Equipment List shall be used.

2.2 The firing mechanism shall be fitted with a device which reliably transmits an electrical signal to initiate timing on a chronograph at the instant of contact between firing pin and primer. The assembly shall also include a separate device (such as electrostatic collector at the muzzle) which transmits an electrical signal at the instant of bullet exit from the muzzle to terminate timing on the chronograph.

3. USE OF REFERENCE CARTRIDGES

3.1 Reference cartridges shall be used to establish range and equipment corrections prior to firing any ammunition lot for acceptance.

3.2 After twenty (20) reference cartridges have been fired in the weapon to be used for the test, the observed mean case mouth pressure and observed mean velocity of the reference cartridges shall be compared with the assessed values. If the assessed value is higher, the

4-2 difference is a plus correction and shall be added to the mean case mouth pressure or mean velocity of the test cartridges. If the assessed value is lower, the difference is a minus correction and shall be subtracted from the mean case mouth pressure or mean velocity of the test cartridges. If both values are identical, no correction is applied.

3.3 Charts shall be maintained of the results obtained with each barrel using reference cartridges.

3.4 The EPVAT barrel assembly shall be withdrawn from service when either of the following performance variations from the assessed value of the reference cartridge is exceeded:

Mean peak case mouth pressure + 25 MPa

Mean velocity + 15 meters/sec

3.5 It is to be noted that barrels shall be retested several times before being finally rejected as out of tolerance.

4. OPERATING PROCEDURE FOR THE BALLISTIC PRESSURE TRANSDUCER

4.1 The case mouth pressure shall be determined by using accepted pressure transducers of the type(s) specified in Appendix A and qualified for use as per Appendices B and C.

4.2 The sensitivity constant for the transducer shall be determined prior to the test and as a minimum, after each successive 140 + 10 cartridges fired on the transducer.

4.3 The transducer shall have its sensitivity determined at the pressure level of 250 MPa.

The pressure units of the hydraulic calibration system, megapascals or pounds per square inch, may determine which nominal pressure level shall be used, i.e., 250 MPa or 36,000 psi. The method for determining the transducer sensitivity is detailed in Appendix B.

4.4 After having determined the sensitivity value for the transducer, the value shall be compared to the sensitivity previously obtained from the very last sensitivity determination.

The last sensitivity having been determined 140 + 10 rounds previous in the life of the transducer, or for a new transducer, the value shall be that obtained from the initial Linearity Test

(refer to Appendix B). If the change in sensitivity is greater than + 2% from the previous value, or more than + 10% from the original value, the transducer shall be disqualified for further testing.

4.5 The transducer sensitivity value to be used for instrumentation scaling shall be the value determined at 250 MPa for the case mouth transducer.

4.6 A record shall be maintained of the sensitivities obtained as a function of the number of cartridges fired on each transducer.

4-3

5. PREPARATION

5.1 The required number of reference cartridges (20) and test cartridges (30) shall be placed in a vertical position, primer end down, in separate recessed holding blocks. Each sample, properly identified, shall be placed in a constant temperature box or room, and shall be conditioned for a minimum of two hours.

5.2 Each barrel shall be borescoped to assess its general condition and to assure that the gas hole is not obstructed. The EPVAT barrel assembly shall be in accordance with the applicable drawings and the following measurements shall be made before it is placed in service, after misfires, pierced primers, blowback, or whenever a part replacement has been made in the bolt assembly.

Limits

Firing pin protrusion 1.52 - 1.73mm

Firing pin indent 0.28 - 0.38mm

Headspace 19.15 - 19.23mm

5.3 The firing range shall be set up as shown on Drawing I. Velocity Screens shall be checked for position. The instrumental point (mid-point between screens) shall be 16 meters from the muzzle.

5.4 The chamber and bore of the barrel shall be wiped dry and the barrel bore sighted into position.

5.5 The transducer mounting holes shall contain no particles of foreign material on the sealing surface. To insure this condition, the following procedure shall be strictly adhered to prior to installing a transducer.

a. Any burrs, combustion particle, residue, corrosion, or other anomaly shall be removed by touching up the sealing surface with a flat end reamer.

b. Clean cavity and transducer thoroughly, use clean, lint-free industrial paper wipers and Freon TF degreaser spray.

5.6 The transducer shall be installed with the EPVAT barrel as per the instructions contained in Appendix A. The signal connector on the transducer and interconnecting line shall be wiped clean with lint-free industrial paper.

5.7 Electronic instrumentation requirements are outlined in Appendix A and calibration procedures are listed in Appendix B.

6. CONDUCTING THE TEST

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6.1 Five fouling shots shall be fired. The pressure, velocity, and action time readings shall be recorded to assure that the measuring equipment is functioning properly. After the fifth fouling shot, the pressure transducer shall be retightened to the appropriate torque level specified in Appendix A. The transducer signal line shall be reconnected and securely tightened finger tight.

6.2 When firing EPVAT at 21C, the recessed holding blocks containing the reference and test cartridges shall be removed from the controlled-temperature room or box and placed at a point convenient to the technician, provided the temperature of the firing room is approximately

21C. If the firing room is not at approximately 21C, or if EPVAT is to be fired for High or Low

Temperature testing, the cartridges shall be placed in an insulated box (five cartridges at a time) which has been conditioned at the required temperature and the box placed at a point convenient to the technician. The cartridges shall then be removed singly from the insulated box immediately before firing. If an insulated box is not available, the cartridges shall be removed singly from the temperature controlled room or box immediately before firing.

6.3 In order that the propellant shall be uniformly positioned from shot to shot, attention to detail is necessary in handling and chambering the cartridge. The cartridge shall first be held vertically, bullet upward. It shall then be rotated slowly in a vertical plane, stopping the rotation momentarily after 180 of rotation when the bullet is downward, and then continuing through the remainder of 360, stopping with the cartridge again bullet end upward. The bullet end of the cartridge shall now be lowered slowly to a position slightly above horizontal.

6.4 The cartridge shall be chambered very carefully, taking care that the primer end of the case is not elevated above the bullet end of the case. (The object is to have the propellant in a loose condition at the primer end of the case, and with such airspace as is present, at the bullet end of the case).

6.5 The breech block shall be closed gently and the trip lever, to which the lanyard is attached, shall be carefully engaged to the hammer. If the technician encounters any difficulty closing the breech block or engaging the trip level, the test shall be discontinued until such difficulty is corrected. If any delay occurs after the cartridge is placed in the chamber, and duration of the delay is such that the temperature of the cartridge has changed significantly, the cartridge shall be extracted and another inserted in its place.

6.6 The technician retires to a safe position and pulls the lanyard with a smooth, firm motion. The velocity, action time, and peak case mouth pressure of the shot shall be recorded.

The breech block shall be opened, the fired case extracted and visually examined for case casualties.

6.7 The procedure prescribed in 6.3 through 6.6 is repeated until the required number of reference cartridges have been fired.

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6.8 The pressure correction and velocity correction shall then be obtained as prescribed in paragraph 3.2

6.9 Provided the requirements of paragraph 3.4 are met, the procedure in paragraph 6.3 through 6.6 is repeated with test cartridges until the required number have been fired.

6.10 At not more than every 140 + 10 rounds fired, the following steps shall be taken:

a. Remove the signal lines from the transducer.

b. Remove the transducer and inspect all components for excessive combustion particle residue; be careful to distinguish between normal combustion residue and metallic particles removed from the bullet jacket. Also inspect the transducer threads for combustion residue.

c. Clean the transducer and cavity thoroughly using lint-free industrial paper wipers and Freon TF degreaser spray. Once cleaned, inspect the sealing surface of the transducer and the cavity for signs of gas flow past the annular Vee ring.

6.11 Upon completion of the above steps, the following procedure shall be followed to restart the test:

a. If the transducer and barrel cavity appear normal, the barrel shall remain qualified for the next 140 rounds of test.

b. If the transducer threads show signs of combustion residue or if any other evidence of gas flow through the sealing surfaces is noticed, the sealing surface of the barrel shall be examined to assure that a 32 microinch finish exists (or better). If the surface finish is poor, the surface shall be machine refinished with a flat end chucking reamer before attempting to use the barrel. The transducer or components at fault shall be replaced so that no gas leakage is experienced. All testing since the last examination shall be refired to assure that the condition did not influence the test results.

c. If the excessive residue and/or bullet jacket particle accumulation is noticed, the

EPVAT barrel shall be removed from test and a retest fired in a replacement barrel to assure that residue fouling did not influence the test results.

7. RECORDING THE RESULTS

7.1 Results of both reference and test cartridges should be recorded directly on the test sheet form. Average velocity shall be recorded to the nearest m/sec., average case mouth pressure shall be recorded to the nearest 1.0 MPa. Individual action time measurements shall be recorded to the nearest .01 millisecond.

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7.2 All groups of data will be tabulated to show means, extreme variations and standard deviation of each group, and the number and type of case casualties.

The following test weapon data shall be recorded on the test sheet:

c. Transducers serial number

d. Total number of cartridges fired in barrel (prior to test).

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5-1

SECTION 5

BULLET EXTRACTION TEST PROCEDURE

1.1 The Bullet Extraction Test determines the force required to pull a bullet from its cartridge case. It is used as a measure of the uniformity and efficiency in which the bullets are secured in the cartridge case.

2.1 Equipment listed in the Bullet Extraction section of the appropriate Inspection

Equipment List shall be used.

3.1 The testing machine should be calibrated either weekly or prior to each occasion of use, whichever is less frequent. Calibration points shall include at least 30 pounds, 60 pounds, 100 pounds, 150 pounds and 250 pounds. If calibration errors exceed 3 pounds at scale readings below 200 pounds, or 6 pounds at scale readings above 200 pounds, then the necessary corrective action shall be taken to reduce the errors below these limits before the bullet extraction test is conducted. The method of calibration shall be by calibrated proof rings or calibrated spring balances which shall yield values within ± 1% of true values over calibrating range.

3.2 The number of cartridges as prescribed by the applicable specification are placed in a recessed holding block which shall be placed at a point convenient to the technician.

4.1 The cartridge shall be inserted into the case holding block on the pulling head and aligned with the jaws on the pulling head. The jaws shall then be secured to the bullet just above the neck of the case.

4.2 The load shall be applied.

4.3 When the bullet has been extracted from the cartridge case, the machine shall be stopped. The force required to extract the bullet, indicated by the tensile indicator, shall be recorded.

4.4 The case and bullet shall then be removed from the holding block and jaws.

4.5 The case, with the propellant, should be placed upright in a recessed holding block and the extracted bullet placed point down in the mouth of the case.

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5.1 The following data shall be recorded.

a. Force required to extract each bullet

b. Average of the individual values

c. Minimum value

d. Maximum value

e. Testing machine data

5-3

Propellant Engineering Proof Testing Record

Bullet Extraction Test

Ammunition:

Type Lot

Army Lot Type

Charge Caliper

Case Bullet

Primer Spec/Auth Wt. Grs

Type of Machine

Rate of Loading – Lbs/min:

Rate of Travel of Pulling Head – Inches/min:

Calibration Points 30 60 100 150 250

Calibration Error

Round

No.

Extraction weight in lbs.

Average

Max

Min

Remarks :

Date of Test

6-1

SECTION 6

FUNCTION AND CASUALTY TEST PROCEDURE

1.1 To insure that the ammunition can be expected to perform satisfactorily in the service weapons for which it has been designed. Ammunition may be ballistically satisfactory, i.e., it may comply with individual specification requirements such as velocity, pressure, trace, etc., yet be unserviceable for use in the field because of undesirable characteristics which jeopardize the safety of user personnel.

1.2 A malfunction is a faulty condition of the ammunition, weapon or its support equipment. A faulty or poorly adjusted weapon can cause casualties in normal ammunition, but if the weapon is in proper condition when casualties are encountered, then the fault is charged to the ammunition. It is important that the weapon be in correct adjustment and in proper condition so that results will not be misleading and any casualties encountered can be attributed to the proper cause.

2.1 Equipment listed in the Function and Casualty section of the appropriate inspection equipment list shall be used.

2.2 Function and casualty weapons required by the item specification together with proper tools for assembly and suitable inspection gages for checking the weapons.

2.3 Firing pin indent of each test weapon shall be measured as follows:

2.4 Firing pin indent shall be measured by placing a copper pressure cylinder, which has been measured for length, in a holding fixture (drawings of copper cylinder, holding fixture and dial gage are referenced in the applicable inspection equipment list). Prior to inserting the copper cylinder in the holding fixture, a zero indicator reading shall be obtained, on the dial gage, on the height of the copper cylinder. The copper cylinder is then placed in the holding fixture. The weapon shall be held in a vertical position, muzzle end down. The bolt or slide shall be retracted to the rearward position and held open. The holding fixture containing the copper cylinder shall then be inserted into the barrel chamber, making certain the copper cylinder retains its original fully seated position in the holding fixture. The bolt or slide shall be manually returned to the battery position and the firing pin released. The bolt or slide shall be retracted very carefully and the holding fixture containing the copper cylinder removed from the chamber. The copper cylinder shall be removed from the holding fixture and the depth of the indent determined by measuring the distance from the original zero indicator reading to the bottom of the firing pin impression. The firing pin indent shall not be off-center more than one half the diameter of the indent.

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2.5 Cyclic rate timer. Suitable recording instrument that will permit measurements within

+ 2% of the true rate of fire. Cyclic rate shall be recorded to the nearest cycle per minute.

3.1 Weapons shall be of the latest design or most recent issue. Receivers for weapons will be considered serviceable until such time as replacement is determined necessary by the gunsmith and verified by the Quality Assurance Representative. Receivers containing metal defects, excessive wear, excessive loosening of component parts, etc., to prevent proper functioning, shall be replaced immediately regardless of accumulated rounds. All barrels shall be inspected dimensionally and visually before use and rejected if any defect is discovered, regardless of accumulated rounds. Barrels for weapons will be considered serviceable until such time as replacement is determined necessary by the gunsmith and verified by the Quality

Assurance Representative. Each weapon and/or barrel considered unserviceable, due to the above, shall be returned to the Quality Assurance Representative with a written report containing reason for turn-in.

3.2 The test cartridges to be loaded into the applicable magazines shall be examined for obvious defects. If visual defects are found, the defective cartridge(s) shall be replaced and the defects shall be noted on the test sheet form.

3.3 Cartridges to be temperature conditioned (high and low temperature) shall be at ambient temperature (16ºC to 27ºC) prior to temperature conditioning and shall be loaded into the applicable magazines and conditioned for no less than one hour.

3.4 For horizontal firings the weapon shall be assembled on the mount and sighted into position. For 80º depression firings the weapon shall be assembled on a suitable mount.

Weapons shall be at room temperature at the start of the test.

3.5 Prior to the horizontal firing, a screen at least 760 x 760mm in size shall be erected at a distance of approximately 15 meters from the gun so that the bullets will pass through the screen near its center. This screen shall be examined, after each weapon is fired, for evidence of stripped bullet jackets. It shall be recovered or replaced as necessary to facilitate observation of the pattern of shots.

4.1 The number of cartridges per burst and the cooling cycle shall be as shown below.

Barrels shall be cooled by air or water to ambient temperature.

4.1.1 Horizontal firings:

Magazine No. of Magazines

Weapon Capacity Magazines Before Cooling

6-3

Pistol 15 3 3

SMG 30 3 3

4.1.2 80º Depression firings:

Magazine No. of Magazines

Weapon Capacity Magazines Before Cooling

Pistol 15 3 3

SMG 30 3 3

4.2 The procedure for firing each of the weapons specified shall be the same insofar as possible. For the horizontal firings the magazine shall be inserted into the weapon and the cartridges fired full automatic where possible (otherwise semi-automatic) and the magazine removed. A time interval of not more than one half minute shall be allowed between magazines.

The next magazine of cartridges shall be inserted and fired semi-automatic. This procedure of alternating automatic and semi-automatic shall be followed (in weapons which permit automatic fire) until the test has been fired. The weapon shall then be cooled to ambient temperature before any further firings take place. For 80 depression firings the initial magazine shall be fired semi-automatic followed by automatic (in weapons which permit automatic fire). This procedure of alternating the method of firing shall be followed until the test has been fired. The weapon shall then be cooled to ambient temperature before any further firings take place.

4.3 At all times, cleaning, lubrication and maintenance of each weapon shall conform ihsofar as possible to the technical instructions provided by the country that provided the weapon. In the absence of specific instructions, cleaning, lubrication and maintenance shall be consistent with good practice for small arms, taking account of any special conditions associated with peculiarities of the weapon, the test, and the type of ammunition. In general, the weapons should be examined frequently for accumulation of brass chips around the extractor, combustion residue in the gas system or other mechanism, excessive fouling in the barrel, and broken or excessively worn parts.

4.4 In the event any stoppage occurs during firing of the test, a detailed check shall be made to determine whether the ammunition or the equipment is at fault. If the stoppage was caused by a misfire, the check of the weapon shall include measurement of the firing pin protrusion and firing pin indent. To assist in determining whether ammunition or equipment is responsible for a stoppage, it is good practice to test the weapon in question using ammunition of known characteristics, and to test the ammunition in question by firing in another weapon of the same type. If it is established that some faulty condition of the weapon is responsible for stoppage, then the test shall be disregarded, the weapon shall be corrected or replaced, and the tests previously conducted with that weapon shall be refired.

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4.5 Upon completion of firing, all cartridge cases from the test ammunition shall be carefully examined for firing defects in accordance with the applicable cartridge specification. If any defect is found, a detailed check of the equipment shall be made to determine whether the ammunition or equipment is at fault. if it is established that a fault weapon is responsible for the firing defect, then the test shall be disregarded, the weapon shall be corrected or replaced and tests with that type of weapon shall be refired.