A 11 ID 2 LL0131

NATL INST OF STANDARDS & TECH R.I.C. REFERENCE

All 1026601 31

Frank, Daniel E/Balllstlc tests of used QC100 .1156 NO.86-3444 1986 V19 C.1 NBS-P . _ _ in doin oo-o444

NBS

PUBLICATIONS

Ballistic Tests of Used Soft Body

Armor

Daniel E. Frank

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Law Enforcement Standards Laboratory

Gaithersburg, MD 20899

August 1986

Issued September 1986

Prepared for National Institute of Justice

QC partment of Justice

2 qq

jton, DC 20531

• U 5 6

86-3444

1986

NBSIR 86-3444

BALLISTIC TESTS OF USED SOFT BODY

ARMOR

Research Information Center

Aational Bureau of Standards

Gaithersburg, Maryland 20899

Ai 8S£-

Q-C/ do

i U-

/TO. % -5<A/UDaniel E. Frank

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Law Enforcement Standards Laboratory

Gaithersburg, MD 20899

August 1986

Issued September 1986

Prepared for National Institute of Justice

U.S. Department of Justice

Washington, DC 20531

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

ACKNOWLEDGMENTS

This report was prepared by the Law Enforcement Standards Laboratory of the

National Bureau of Standards under the direction of Lawrence K. Eliason, Chief of LESL.

The National Institute of Justice Technology Assessment Program (TAP) Information Center

awarded the contract and monitored the ballistic testing described in this report, which

was conducted by H. P. White Laboratory, Inc., Street, MD 21154. Mr. Brad Stimson,

National Research Council of Canada, Public Safety Project Office, participated in the

test design and witnessing of the actual testing. The contributions of Marc Caplan, TAP

Information Center are likewise acknowledged. The research was sponsored by the

National Institute of Justice, Lester D. Shubin, Standards Program Manager. The

technical effort to develop this report was conducted under Interagency Agreement

LEAA- J-IAA-021-3 , Project No. 7101.
,

.

*
FOREWORD

I

The Law Enforcement Standards Laboratory (LESL) of the National Bureau of Standards

(NBS) furnishes technical support to the National Institute of Justice (NIJ) program to

strengthen law enforcement and criminal justice in the United States. LESL's function

is to conduct research that will assist law enforcement and criminal justice agencies in

the selection and procurement of quality equipment.

LESL is: (1) Subjecting existing equipment to laboratory testing and evaluation

and (2) conducting research leading to the development of several series of documents,

including national voluntary equipment standards, user guides and technical reports.

This document presents the results of a joint NIJ and National Research Council

( NRC ) of Canada effort to evaluate the effect of age upon the ballistic-resistant

capabilities of police body armor. The testing program was administered by the NIJ

Technology Assessment Program Information Center assisted by LESL in support of NRC and

NIJ.

Technical comments and suggestions concerning this document are invited from all

interested parties. They may be addressed to the author or to the Law Enforcement

Standards Laboratory, National Bureau of Standards, Gaithersburg, MD 20899.

Lawrence K. Eliason, Chief

Law Enforcement Standards Laboratory

iii
,

•
CONTENTS

Page

Foreword iii

1. Introduction 1

2 . Background 2

3. Ballistic Resistance Test Methods 4

4. Test Specimens 6

5. Test Results 9

6. Discussion 16

7. Conclusions 19

8. References 20

Appendix A—

V

5Q Ballistic Limit Test Data, Seven Layer Kevlar Soft Body Armor,

38 Caliber, 158 Grain, Lead Round Nose Projectile 21

Appendix B--V5Q Ballistic Limit Test Data, Seven Layer Kevlar Soft Body Armor,

22 Caliber, 40 Grain, Lead Round Nose Projectile 28

v
COMMONLY USED SYMBOLS AND ABBREVIATIONS

A ampere H henry nm nanometer

ac alternating current h hour No. number

AM amplitude modulation hf high frequency o.d. outside diameter

cd candela Hz hertz (c/s) Cl ohm cm centimeter i.d. inside diameter P- page CP chemically pure in inch Pa pascal

c/s cycle per second ir infrared pe probable error d day J joule pp. pages dB decibel L lambert ppm part per million dc direct current L liter qt quart

°C degree Celsius lb pound rad radian °F degree Fahrenheit lbf pound-force rf radio frequency

diam diameter lbf-in pound-force inch rh relative humidity

emf electromotive force lm lumen s second

eq equation In logarithm (natural) SD standard deviation F farad log logarithm (common) sec. section

fc footcandle M molar SWR standing wave radio

fig- figure m meter uhf ultrahigh frequency

FM frequency modulation min minute uv ultraviolet

ft foot mm millimeter V volt

ft/s foot per second mph mile per hour vhf very high frequency

g acceleration m/s meter per second W watt g gram N newton X wavelength

gr grain N-m newton meter wt weight

area = unit2 (e.g., ft

2

, in2, etc.); volume = unit 3 (e.g., ft

3

, m

J

, etc.)

PREFIXES

d deci (10' 1 ) da deka (10) c centi ( 10'2

) h hecto (10

2 ) m milli (10-3

) k kilo (103

) P micro (10*6

) M mega (10

6

) n nano (1C)'

9

) G giga (10

9

) P pico (10

12

) T tera (10 12

)

COMMON CONVERSIONS

(See ASTM E380)

ft/s X 0.3048000 = m/s

ft X 0.3048 = m

ft-lbfX 1.355818 = J gr X 0.06479891 =g

in X 2.54 = cm kWhx3 600 000 = J

lbx0.4535924 = kg

Ibfx 4.448222 = N

lbf/ftX 14.59390= N/m

lbf-mX 0.11 29848 = N-m

lbf/in 2 X 6894.757 = Pa mph X 1 .609344 = km/h

qtX 0.9463529 = L

Temperature: (T-f-32)X 5/9 = T-c

Temperature: (T-c X 9/5) + 32 = T-p

vi
Ballistic Tests of Used Soft Body Armor

* Daniel E. Frank

National Bureau of Standards

Gaithersburg, MD 20899

A sample of 24 ballistic resistant undergarments (soft body armor) from a production lot of 1500 originally distributed to 15 police departments

throughout the United States in 1975 for issue to officers as part of a Law

Enforcement Assistance Administration demonstration project, was tested for

V

5Q ballistic limit. The program was a joint effort of the U.S. Department of

Justice National Institute of Justice and the National Research Council of

Canada Public Safety Project Office. Tests of ballistic limit were conducted

on virgin armor that were never issued, and armor showing evidence of light,

moderate, and heavy wear both dry and while wet. The results show that armor

does not lose ballistic efficiency as a consequence of age.

Key words: ballistic limit; ballistic-resistant body armor; ballistic

testing; body armor; Kevlar; soft body armor

1 . INTRODUCTION

1

Soft body armor suitable for routine full time use by police officers became

available in quantity in the mid 1970 's following development by the National Institute

of Justice (NIJ), previously the National Institute of Law Enforcement and Criminal

Justice of the Law Enforcement Assistance Administration. In the interim, soft body

2 armor manufactured from Kevlar aramid fiber fabric has gained widespread use. While

* Law Enforcement Standards Laboratory, National Engineering Laboratory.

1 The use of trade names in this report does not constitute endorsement by the

National Bureau of Standards, the U.S. Department of Justice, or any other government

agency; nor does it imply that a product is necessarily best suited for the intended

use

2 Registered trade name of E. I. Du Pont de Nemours & Co., Inc.

1
exact statistics are not available it is estimated that more than 50 percent of the

nation's police have been issued body armor, or have purchased it themselves.

Many police departments are currently continuing to use armor that was purchased

prior to 1975. Although there has never been a reported incident of armor manufactured

from Kevlar failing to protect an officer when assaulted with a weapon having a ballistic threat equal to or less than the rated protection of the armor, those

departments with older armor are increasingly concerned with the effect of age and wear upon Kevlar fabric.

During the last year, the NIJ Technology Assessment Program (TAP) Information

Center, and the National Research Council of Canada (NRC) Public Safety Project Office

have received numerous inquiries from police agencies questioning whether it is

necessary to replace older existing armor to be sure that their officers are properly

protected. In response to these questions, NIJ and NRC requested that the National

Bureau of Standards Law Enforcement Standards Laboratory ( LESL ) collaborate with the TAP

Information Center to conduct tests of soft body armor that had been in service for

extended periods of time. The discussion that follows describes the testing program

that was conducted and presents the results of this effort.

2 . BACKGROUND

The NIJ, aware of the rapidly increasing number of officer fatalities through

handgun assault during the late 1960's and early 1970 's recognized that the physical

properties of Kevlar held potential for ballistic resistance. Preliminary experiments

demonstrated that Kevlar was highly efficient in ballistic resistance and NIJ launched

an effort to develop soft body armor that was suitable for routine full time use by

police officers.

The objective of the development effort was to design armor that would protect

officers from the most common handgun threats of that time, the 38 caliber bullet at a velocity of 850+50ft/s, and the 22 caliber bullet at a velocity of 1050+50 ft/s.

Experiments were conducted to determine the minimum number of layers of Kevlar required

2
to provide the desired ballistic protection, and it was found that seven layers were

suitable. Since Kevlar fabric was not available in commercial quantity at the time, NIJ

awarded contracts to several weavers to produce large quantities of the fabric.

Following this, NIJ awarded contracts to several manufacturers to produce

ballistic-resistant undergarments in accordance with the NIJ design specification. A

total of 3000 such garments of two designs were manufactured, together with 2000

additional garments of several other types of soft body armor.

In order to prove that the new armor was effective in protecting the officers from

handgun assault, and that it was suitable for full time routine use throughout the

United States, NIJ distributed the armor to 15 cities throughout the United States. The

resulting field test verified that all of the objectives of the NIJ development effort

3 had been met [1] , and body armor manufacturers began to actively market the new armor.

During the time that NIJ developed the new soft body armor, LESL developed a performance standard for body armor, which was promulgated by NIJ as a voluntary

national standard in 1973. Since then, the NIJ standard, which has been revised twice

to remain current with technology, has been widely used both domestically and

internationally as the basis upon which body armor is purchased.

During the course of its development effort, NIJ was careful to document the

details of the experimental effort. Thus, data were available concerning the

ballistic-resistant characteristics of the original production lots that would enable

valid conclusions concerning the effect, of age and wear, if any, upon the ballistic

efficiency of those vests if samples could be obtained for laboratory tests.

The TAP Information Center contacted each of the 15 cities that had been given

undergarments during the NIJ demonstration program and requested a search of property

records to determine if any of the vests were still in their possession. In addition,

NIJ examined its own property records and requested that other Federal agencies that

purchased armor in parallel with the NIJ program do the same.

3 Numbers in brackets refer to references in section 8 of this report.

3
Five cities located armor from the original NIJ purchase, some still in actual use and some in inventory. Similarly, NIJ and two other Federal agencies were able to

locate armor manufactured at that time, some of which was never worn.

3. BALLISTIC RESISTANCE TEST METHODS

The physical characteristics of Kevlar fiber, and the fabric woven from it, vary

somewhat from lot to lot and even within a lot, as with any item of manufacture. As a consequence, when multiple layers of fabric are used to construct soft body armor the

ballistic resistance of individual vests of the same design varies from one to another.

The NIJ standard for ballistic resistant police body armor establishes minimum

performance requirements. To this end, body armor is tested by firing specific types of

bullets against armor samples using closely controlled velocities. Armor that is not

penetrated by the required test rounds and does not deform more than 1.73 in upon impact

is considered to meet the requirements of the standard. Because soft body armor manufactured from fabric is known to lose ballistic efficiency when it is wet, and since

officers do get wet, the armor model is tested both dry and while wet.

The NIJ standard for body armor can be used as the basis for tests to determine

whether armor complies with the minimum performance requirements as specified, but the

test results do not provide a knowledge of the ultimate ballistic protection that a given sample of body armor may provide. Frequently manufacturers will incorporate more layers of fabric than required for minimum performance to ensure that the armor will

meet the ballistic requirements even if a given lot of fabric is slightly less

ballistically efficient than normal.

In order to examine the relative ballistic performance of armor, rather than simply

verifying minimum performance, it becomes necessary to use a different method of test.

The armor industry has typically used the ballistic limit as the means of comparing

the ultimate performance of armor materials.

4
V

50 ballistic limit is the velocity at which a specific projectile (bullet) is

expected to penetrate the armor half of the time.

The ballistic limit of armor is most frequently conducted using the procedures of

MIL-STD-662D [2]. Essentially, the specified test projectile is fired at the armor over

a range of impact velocities and the specimen examined after each impact to determine

whether the projectile has penetrated the armor or not. While the standard permits

different velocity ranges from the highest velocity test round to the lowest, a total

velocity range of 125 ft/s is most commonly used for the test. In practice, the first

projectile is fired at a velocity controlled so as to yield an impact velocity near that

of the expected V^q. If the first projectile penetrates the velocity of the second test

round is reduced and the impact point examined for penetration. Conversely, if the

first projectile does not penetrate, the velocity of the second round is increased and

the impact point examined for penetration. The objective is to fire a total of 10

projectiles at various velocities to obtain 10 impacts; five of which penetrate and five

of which do not within an overall velocity range of 125 ft/s. The ballistic limit

is then calculated as the average velocity of the 10 test rounds.

The test results presented in this report were obtained using the procedures of

MIL- STD- 6 6 2D.

The NIJ standard for police body armor requires the evaluation of both the

penetration resistance of body armor and the deformation of the armor caused by the

bullet impact. The deformation, which is measured as the depth of the indentation in

the clay backing material at the point of a nonpenetrating impact, is determined to ensure that an individual wearing the armor will be protected from blunt trauma.

Specifically, NILECJ-STD-0101 . 01 , Ballistic Resistance of Police Body Armor [3]

(the test method used to obtain some of the results presented in this report) requires

that the deformation not exceed 1.73 in for Type I armor when impacted with a 40 grain

lead round nose 22 caliber bullet at a velocity of 1050+50 ft/s and a 158 grain lead

round nose 38 caliber bullet at velocity of 850+50 ft/s.

5
The deformation measurements were included in the experimental design to determine

whether deformation might be an early indicator of ballistic deterioration, should used armor exhibit a significant loss in ballistic efficiency.

4 . TEST SPECIMENS

The 24 sets of body armor tested in this program were all of the same design as shown in figures la and lb and the vests were constructed of seven layers of 1000

2 denier, 31x31 plain weave Kevlar fabric, which was waterproofed with Zepel D .

Figure la. Front of vest outside and inside.

6
Figure lb. Back of vest outside and inside.

During manufacture, the two outer layers of Kevlar fabric and the exterior cover

were cut to the finished size. The five interior layers were cut slightly smaller than

the outer layers. The interior Kevlar layers were first stitched together at a number

of points near the edge of the fabric. The interior layers were then placed between the

two outer Kevlar layers and the front cover and the assembly was completed by sewing

bias tape around the entire edge attached to the outer Kevlar layers, which extended

approximately one-half inch beyond the edge of the interior layers.

The back panel construction was identical to that of the front panel as described

above; however, in addition, the back panel was reinforced by vertical stitching from

top to bottom at intervals of approximately 4 in from one side to the other.

Each vest was clearly labeled "LEAA Prototype Protective Garment," which enabled

verification that the garment was indeed from the original LEAA demonstration production

lot.

While the property records of the five police departments were sufficiently

accurate to locate the test specimens, it was generally not possible to obtain accurate

information concerning the wear and maintenance details for the individual vests. This
was a consequence of the fact that the individuals that were issued the vests were no longer on their respective forces and efforts to locate the officers were unsuccessful.

It was possible to obtain limited use information for only seven of the vests.

Five of the vests (15, 17, 18, 20, and 21) were obtained from a department with a very

hot, moderately humid climate. These vests were issued upon receipt from LEAA in 1975

and were still in service when recalled for testing in April 1986--a service period well

over 10 years. The department policy was one of voluntary use, however, the department

believes that the officers that wore the vests did so full time except for the hottest

months of the summer.

Vest 6 which came from a department with a generally hot, humid climate, was worn

by three different officers. The first officer had the vest for over a year and

one-half; however, its use was not known. The second officer wore it full time while on duty for approximately two years, wiping it with a damp sponge and soap and never machine washing it. The last officer wore it for a one-year period but the extent of wear is not known.

Vest 9 which came from a department with a very hot humid climate, was used by the

first officer of issue for over three and one-half years. There is no information on the extent of use. The vest was subsequently issued to an auxiliary officer that wore

it full time while on duty for a period of five years. However, this officer was only

on duty a few days each month.

In the absence of detailed use information, it became necessary to rely upon visual

inspection to estimate the extent of use. Eight of the 24 test specimens were unused.

Representatives of NIJ, LESL, and the TAP Information Center examined each of the

remaining 16 specimens that had been used. It was possible to separate the vests into

three groups;

o Four exhibited light wear

o Four exhibited moderate wear

o Eight exhibited heavy wear

8
Once the test specimens were classified in accordance with use (unused, light wear,

moderate wear, heavy wear), they were randomly assigned to two test groups. One group

was scheduled for ballistic test using 38 caliber ammunition, the other for tests using

22 caliber ammunition. Finally, half of the vests in each group were scheduled for

ballistic tests while wet and the other half for ballistic tests while dry.

5 . TEST RESULTS

The testing of used armor was conducted by the H. P. White Laboratory, Inc.,

Street, Maryland, during the period from May 22 to June 10, 1986. Representatives of

the TAP Information Center, the National Research Council of Canada, and LESL witnessed

all testing.

The test samples were mounted at a distance of 16.0 ft from the test weapon on clay

backing as specified by NILECJ-STD-0101 . 01 to produce a zero degree angle of obliquity.

The first shots on each panel were to determine the back face signature (clay

deformation) in accordance with NILECJ-STD-0101 . 01 after which the V^q of the panel was

determined. Light screens were positioned at 6.5 and 9.5 ft which, in conjunction with

an elapsed time counter (chronograph), were used to determine all bullet velocities at

8.0 ft.

In conducting ballistic limit tests of the 24 samples, the front and back panels of

each vest were tested separately. Every effort was made to obtain 10 valid impacts for

the determination of V^q ballistic limit. However, there were a number of instances in

which the shot placement was such that it was not possible to obtain 10 valid impacts

and, in these cases, 8 shot ballistic limit data are reported. Similarly, there were instances in which the inspection of the vest at a later date revealed that an impact used to calculate a 10 shot V^q ballistic limit was not a valid impact and the

data was recalculated on the basis of an 8 shot V,-q.

Table 1 summarizes the ballistic limit for each vest tested using 38 caliber

bullets. Following completion of the tests, vest 22 was reinspected and found to

contain eight layers of Kevlar, rather than the specified seven layers. Table 2

9
presents the blunt trauma deformation measurements that were obtained using 38 caliber

bullets.

Table 1. V,.q ballistic limit data,

38 caliber, 158 grain, lead round nose bullet

(V^q expressed in feet per second)

Unused vests Light wear vests Moderate wear vests Heavy wear vests

Sample V

50 Sample V50

Variation

from unused

vest average

(percent) Sample V

50

Variation

from unused

vest average

(percent) Sample

Variation

from unused

vest average

V

5Q (percent)

IF 1074 33F 1104 +3.2 10F 1108 +3.6 17F 1153 +7.8

IB 1075 33B 1135 +6.1 10B 1165 +8.9 17B 1075 +0.5

23F 1036 12F

C 1126C +5.2 30FC 1120 +4.7 31F 1131 +5.7

24B 1050 12B

C

1 1 12

c +3.9 30BC 1118 +4.5 31B 1152b +7.7

4F

C 1088 Average 1119 +4.6 Average 1128 +5.4 18F

C 1080 +0.9

4B

C 1095 18B

C 1074 +0.4

Average 1070 13F

C

1 1 59

b +8.3

22Fa,C1 16 l a 13B

C 1129b +5.5

22Ba,C1193 Average 1119 +4.6

aSample 22 contained eight layers of fabric, excluded from average.

bEight shot Vj-q determination.

C Tested wet.

10
Table 2. Deformation measurements, 38 caliber projectile

Unused vests Light wear vests

Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in) Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in)

IF 895 1.65 33F 880 1.40

887 1.50 893 1.40

IB 850 1.60 33B 874 1.50

877 1.45 888 1.35

23F 867 1.50 12F

a 892 1.45

884 1.50 897 1.50

24B 895 1.50 12B

a 842 1.70

871 1.60 823 1.65

4F

a 888 1.60

866 1.60

4B

a 867 1.60

869 1.60

22F

a 896 1.60

875 1.40

22B

a 881 1.30

902 1.45

aTested wet.

Moderate wear vests Heavy wear vests

Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in) Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in)

10F 855 1.50 17F 860 1.50

885 1.60 872 1.60

10B 885 1.60 17B 867 1.50

898 1.45 889 1.30

30F

a 837 1.45 31F 875 1.45

839 1.65 881 1.50

30B

a 854 1.40 31B 877 1.35

837 1.60 885 1.50

18F

a 872 1.60

877 1.60

18B

a 882 1.65

882 1.50

13F

a 821 1.50

828 1.60

13B

a 837 1.50

834 1.55

Note: All velocity measurements rounded to nearest foot per second.

Table 3 summarizes the V^q ballistic limit for each vest tested using 22 caliber

bullets, and table 4 presents the blunt trauma deformation measurements obtained with 22

caliber bullets.

11
Table 3. V,.q Ballistic Limit Data

.22 caliber, 40 grain, lead round nose bullet

(V^q expressed in feet per second)

Unused vests Light wear vest Moderate wear vests Heavy wear vests

Sample V

50 Sample V50

Variation

from unused

vest average

(percent) Sample V

50

Variation

from unused

vest average

(percent) Sample V

50

Variation

from unused

vest average

(percent)

2F 1179 15F 1219 +1.6 32F 1238 +3.2 20F 1160 -3.3

2B 1203 15B 1267 +5.6 32B 1224 +2.0 20B 1172 -2.3

25F 1200 21F

b 1214 +1.2 7F

b 1183 -1.4 8F 1200 0

25B 1217 21Bb 1239 +3.3 7B

b 1251 +4.3 8B 1205 +0.4

3F

b 1169 Average 1235 +2.9 Average 1224 +2.0 9F 1183 -1.4

3B

b 1164 9B 1154 -3.8

26B

b 1260 6F 1182 -1.5

27F

b 1210 6B 1137

a -5.3

Average 1200 Average 1174 -2.2

Dry retest. Initial wet test, not included not included

in average in average

3F 1102 9F

b 1183 -1.4

3B 1182 9B

b 1099 -8.4

6F

b 1075

a -10.4

6B

b

1 145

a -4.6

aEight shot determination.

^Tested wet.

12
Table 4. Deformation measurements, 22 caliber projectile

Unused vests Light wear vests

Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in) Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in)

2F 1064 0.80 15F 1054 0.80

1063 0.85 1115 0.90

2B 1096 0.90 15B 1101 0.55

1063 0.85 1083 0.60

25F 1077 0.85 21F

a 1058 0.80

1054 0.80 1083 0.85

25B 1051 0.80 21Ba 1066 0.80

1070 0.85 1066 0.75

3F

a 1049 0.85

1071 0.95

3B

a 1071 0.75

1103 0.80

26B

a 1083 0.75

1073 0.70

27Fa 1101 0.85

1038 0.75

1064 0.75

Moderate wear vests Heavy wear vests

Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in) Sample

Average

Impact

Velocity

(ft/s)

Deformation

(in)

32F 1029

1085

0.90

0.85

20F 1075

1067

0.70

0.65

32B 1066

1068

0.80

0.80

20B 1057

1063

0.80

0.70

7F

a 1054

1085

0.80

0.80

8F 1058

1081

0.85

0.75

7B

a 1040

1038

0.80

0.85

8B 1040

1081

0.75

0.25

9F

a 1059

1053

0.20

0.75

9B

a 1095

1060

0.80

0.80

6F

a 1054

1049

b

b

6B

a 1068

1085

0.80

0.65

aTested wet.

^No measurement, test round penetrated armor.

Note: All velocity measurements rounded to nearest foot per second.

Table 5 expands upon the ballistic limit data summarized in table 1, to include the

velocity of the highest velocity nonpenetrating round (H ), the velocity of the lowest

P

velocity complete penetration round (L

c

) and the velocity range of mixed results of

penetrating and nonpenetrating rounds for 38 caliber bullets.

13
Table 5. Complete ballistic limit data, 38 caliber

Unused vests

Sample

no

.

V

50

( ft/s)

H

P

( ft/s)

L

c (ft/s)

Range

mixed

(ft/s)

IF 1074 1113 1031 82

IB 1075 1073 1075 N/A

23F 1036 1083 988 95

24B 1050 1079 1036 43

4Fa 1088 1109 1064 45

4Ba 1095 1087 1105 N/A

22Aa 1161 1147 1170 N/A

22Ba 1193 1238 1149 89

Light wear vests

Sample

no

.

V

50

( ft/s)

H

P

(ft/s)

L

c (ft/s)

Range

mixed

( ft/s)

33F 1104 1181 1062 119

33B 1135 1167 1111 56

12Fa 1126 1113 1113 0 12Ba 1112 1097 1095 2

Medium wear vests

Sample

no.

V

50

(ft/s)

H

P

( ft/s)

L

c (ft/s)

Range

mixed

(ft/s)

10F 1108 1163 1091 72

10B 1165 1220 1101 119

3 0Fa 1120 1165 1093 72

3 0Ba 1118 1138 1093 45

Heavy wear vests

Sample

no.

V

50

(ft/s)

H

P

(ft/s)

L

c (ft/s)

Range

mixed

(ft/s)

17F 1153 1163 1154 9 17B 1075 1107 1062 45

31F 1131b

1174 1060 114

31B 1152b1208 1132 76

18F 1080 1097 1064 33

18Ba 1074h

1097 1062 35

13Fa H59b1222 1158 64

13B 1129° 1210 1103 107

aTested wet.

bEight shot Vj-q.

Table 6 expands upon the ballistic limit data summarized in table 3,

L

c

, and range of mixed velocities for 22 caliber bullets.

including Hp,

14
Table 6. Complete ballistic limit data, 22 caliber

Unused vests Medium wear vests

Sample

no

.

V

50

( ft/s)

H

P

( ft/s)

L

c

( ft/s)

Range

mixed

(ft/s)

Sample

no.

V

50

(ft/s)

H

P

( ft/s)

L

c

( ft/s)

Range

mixed

(ft/s)

2F 1179 1202 1165 37 32F 1238 1268 1215 53

2B 1203 1238 1188 50 32B 1224 1258 1192 66

25F 1200 1245 1174 71 7F 1183 1156 1154 02

25B 1217 1255 1176 79 7Ba 1251 1261 1230 31

3Fa 1169 1176 1152 24

3Ba 1164 1195 1143 52

26Ba 1260 1288 1232 56

27Fa 1210 1238 1160 78

Retest (Dry)

3F 1102 1085 1085 0

3B 1182 1220 1170 50

Light wear vests Heavy wear vests

Sample

no

.

V

50

(ft/s)

H

P

( ft/s)

L

c (ft/s)

Range

mixed

(ft/s)

Sample

no.

V

50

(ft/s)

H

P

(ft/s)

L

c (ft/s)

Range

mixed

( ft/s)

15F 1219 1220 1220 0 20F 1160 1147 1145 2 15B 1267 1290 1260 30 20B 1172 1174 1172 2 21Fa 1214 1242 1198 44 8F 1200 1222 1176 46

21Ba 1239 1248 1240 8 8B 1205 1220 1195 25

9F 1183 1181 1154 27

9Ba 1099 1147 1075 72

6Fa 1075° 1091 1049 42

6B 1145° 1172 1115 57

Retest (Dry)

9F 1183 1198 1160 38

9B 1154 1178 1136 42

6F 1182 1192 1155 37

6B 1137° 1165 1143 22

£Tested wet.

bEight shot V^q.

Appendix A presents the raw data for each sample that was tested using 38 caliber

projectiles, noting the impact velocity of each bullet that was fired to determine the

V^q ballistic limit, whether or not it penetrated, and identifies those test rounds used

to calculate the V

5Q ballistic limit. Test rounds associated with deformation testing

(see tables 2 and 4) are not included. Appendix B presents the same penetration data as appendix A but for 22 caliber projectiles under the same limitations as appendix A.

15
Those test rounds reported in appendix A and B that were not used to obtain the VCrt oO

ballistic limit were excluded from calculation for a variety of reasons, including 1)

hitting too close to an edge or prior hit, 2) projectile yaw, and 3) outside of the

desired maximum velocity range.

6. DISCUSSION

When tested following the procedures of NILECJ-STD-0101 . 01 , the deformation

measurements that were made for all samples were well within the specified maximum limit

of 1.73 in. There was no apparent difference between dry testing and wet testing. From

these tests we concluded that impact deformation does not appear to hold promise as an early indicator of loss of ballistic resistant efficiency.

The interpretation of the V^q ballistic limit data for the vests that were evaluated can be considered somewhat subjective because the data are too limited to

permit rigorous statistical analysis. However, the following was derived from this

series of tests.

The average V^q ballistic limit for the 38 caliber test rounds of the 10 year old

unused armor is 1070 ft/s, excluding vest 22, which consists of eight layers of Kevlar.

The standard deviation of the V,- 0 is 22.6 ft/s, with an overall range of 59 ft/s. There

is no obvious difference within any of the four wear groups (new, light wear, moderate

wear, or heavy wear) between tests conducted with the armor wet or dry.

When the V

5Q ballistic limit of each of the used vests is compared to the average

of the unused vests of the same construction, in all cases the used vest has a higher

V

50 *

When the average V

5Q of the three used vest groups (wet and dry testing avenged

together) is compared with that of the unused armor, each of the three used vest groups

exhibit V

5Q roughly 5 percent higher.

16
V^

0 ballistic limit data for the 158-grain lead round nose bullet was not reported

in testing conducted by Edgewood Arsenal during the earlier LEAA development effort;

however, partial data [4] imply a V

5Q ballistic limit on the order of 1000 ft/s. Since

the tests were conducted with fabric not sewn together, one would expect a higher V

5Q

for the finished vests that were tested, and the values of V,- 0 ballistic limit that were obtained are consistent with the earlier data.

It is perhaps of more interest to examine the test results in terms of the velocity

of the lowest complete penetration for each panel, for this gives a better idea of

absolute ballistic resistance relative to the rated threat level. The test velocity for

the determination of penetration for a Type I vest is 850+50 ft/s, or a maximum velocity

of 900 ft/s. With one exception, all of the vests that were tested demonstrated a velocity for the lowest velocity complete penetration more than 150 ft/s above that

required for minimum performance. Even the poorest performing armor sample (vest 23

front) exceeded the 900 ft/s requirement by a velocity of 88 ft/s.

As with the 38 caliber testing of V

5Q ballistic limit, there did not appear to be

any overall difference between 22 caliber tests conducted wet and dry, other than

discussed below. The overall average V^q ballistic limit using the 22 caliber 40 grain

lead round nose bullet was 1200 ft/s with a standard deviation of 31 ft/s and an overall

range of 96 ft/s. Earlier data from Edgewood Arsenal [3] reports a ballistic limit

for seven layers of Kevlar 1000 denier fabric of 1084 ft/s. Again, these tests used

fabric only and the ballistic limit of the fabricated vests would be expected to exceed

that reported. The same Edgewood report presents a V,-q ballistic limit of seven layers

of 1140 denier Kevlar of 1213 ft/s. This fabric is similar to 1000 denier in ballistic

efficiency, although, it was not treated for water repellency. Since the overall

ballistic efficiency of treated Kevlar is known to be less than untreated, the average

V,-q of 1200 ft/s is reasonable for the unused armor that was tested in this program.

When first tested wet, the front panel of vest 6 was penetrated at velocities of

1054 and 1049 ft/s and the V^q ballistic limit was 1075 ft/s; well below the 1100 ft/s

upper limit of threat Type I protection (1050+50 ft/s). Likewise, the V

5Q ballistic

limit of the back panel of vest 9 was 1099 ft/s which is marginal performance at best.

Since all other vests tested with 22 caliber bullets were found to have V^

0 ballistic

17
limits well in excess of 1100 ft/s, the data for vests 6 and 9 were suspect. Similarly,

vest 3, also tested wet, appeared to have a somewhat low V

5Q ballistic limit, when

compared to the other unused vests.

Vests 3, 6, and 9 were allowed to dry in a well ventilated, controlled environment

for several days, and once feeling dry to touch, were retested dry for ballistic limit

using the 22 caliber ammunition. The two panels in most question, 9B and 6F, when

retested dry, demonstrated V^q ballistic limits well above 1100 ft/s, as did the lowest

velocity complete penetrating rounds. The other parts of these vests continued to

demonstrate satisfactory V^q ballistic limit and lowest complete penetrating velocity,

when dry.

The retest of vest 3 was not conclusive. The V^q ballistic limit of the back panel

increased slightly when retested; however, that of the front panel decreased. While the

placement of the bullet impacts during retest were sufficiently distant from prior

impact locations to constitute fair hits, it remains possible that the previous testing

prevented obtaining valid data in the second set of tests (see fig. 2).

Figure 2. Front of vest 3 after being shot.

18
Overall, as with the 38 caliber testing, the ballistic limit of the light and

moderate wear samples tested with 22 caliber bullets increased when compared with the

average of the unused samples. The heavily worn vests had an average V^q ballistic

limit of 1174 ft/s (using data for vest 6 and 9 tested dry), 2.2 percent less than the

average 1200 ft/s ballistic limit of the unused vests.

7 . CONCLUSIONS

Body armor manufactured from Kevlar fabric retains full ballistic efficiency when

stored under typical warehouse conditions for periods of time in excess of 10 years. It

may well be, as anticipated, that such armor has an unlimited shelf life.

Deformation measurements using wet or dry armor do not appear to provide

significant information as a means of identifying decreased ballistic efficiency of used

armor manufactured from Kevlar fabric.

Two of the sample vests that were tested for ballistic limit did not appear to have

adequate waterproofing. It is not known whether this was a consequence of heavy wear or improper water repellent treatment at the time of manufacture.

Both the 38 caliber and 22 caliber ballistic limit data support an apparent trend

of improved ballistic efficiency as a consequence of light to moderate wear and possibly

a slight decrease in ballistic efficiency as a result of heavy wear. The limited data

that were obtained and the variation of ballistic efficiency within lots of Kevlar

fabric is such that it is very difficult to say with certainty that the difference

between the Vj-q of unused and heavily used vests is solely a consequence of wear, or due

to the individual samples. Recent data obtained from the U.S. Army [5] for V

5Q

ballistic limit of 16 production lots of Kevlar fabric (12-layer test samples tested

using the 22 caliber fragment simulator) demonstrate ranges of V

5Q ballistic limits of more than 6 percent between individual lots.

The possible trend of decreased ballistic efficiency of armor following heavy use,

coupled with the identification of at least two armor panels that lacked waterproofing.

19
strongly suggest that it is prudent for any police department to inspect the vests worn

by its officers on at least an annual basis. Representative samples of vests showing

extremely heavy wear should be tested for ballistic performance. Such tests should be

conducted with the vests in the wet condition. In the interest of minimizing testing

cost, it is recommended that such testing be limited to the six shot test sequence

specified by the current edition of the NIJ Standard using a single test round (22

caliber for Type I vests and 9 mm for Level IIA, II, and IIIA vests).

8 . REFERENCES

[1] Body armor field test and evaluation final report. Vol. I, Executive Summary.

Aerospace Corporation, Law Enforcement and Telecommunications Division, Washington,

DC; 1977 September.

[2] Ballistic test for armor. Military Standard MIL-STD-662D. U.S. Army Materials and

Mechanics Research Center, Watertown, MA 02172; 1984 March 19.

[3] Ballistic resistance of police body armor. NILECJ-STD-0101 . 01 . National Institute

of Justice, U.S. Department of Justice, Washington, DC 20531; 1978 March.

Superseded by NIJ Standard-0101.02, Ballistic Resistance of Police Body Armor dated

March 1985.

[4] Prather, R. N. , Swain, C. L. , Hawkins, C. E. Back face signatures of soft body

armors and the associated trauma effects. RCSL-TR-77-55 . Chemical Systems

Laboratory, Aberdeen Proving Ground, MD; 1977 November.

[5] Personal communication with the Defense Personnel Support Center, Philadelphia, PA.

20
APPENDIX A

Vj-q Ballistic Limit Test Data

Seven Layer Kevlar Soft Body Armor

38 Caliber, 158 Grain, Lead Round Nose Projectile

21
Sample 1 (unused) ; tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

4 1026 3 1143 3 1005 6 107 5 a

5 1081 6 1218 4 995 8 1138 a

8 1077 a 7 1085 a 5 1073 a 10 1089 a 10 1081a 9 108 l a 7 906 11 lllla 13 1075a 11 1064 a 9 1022 a 13 1178

14 1113 a 12 103 l a 12 1058 a 15 1158

16 1036 a 15 1097 a 14 102 6 a 16 1124 a 17 103 l a

Sample 4 (unused) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

4 1109 a 3 1202 4 1014 3 1143 a

9 107 3 a 5 1188 5 1020 6 1156a 10 1068 a 6 1070a 8 984 7 1105 a 11 1051 a 7 1 14 9 a 9 1054 a 10 llll a 12 1022 a 8 1130 a 12 1054 a 11 1130 a 13 1149 a 13 977

14 1064 a 14 1054 a 15 1024

16 1087 a 17 1058 a

aUsed to calculate V

5Q ballistic limit.

22
Sample 10 (moderate wear) ; tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 1075 a 4 104 l a 5 1077 7 1277

5 1163a 6 1103 a 6 1073 8 1160 a

8 949 7 1132 a 10 974 9 12 08 a

9 932 11 114 l a 11 113 6 a 12 1210 a 10 1119 a 12 1145 a 13 1158 a 15 12 10 a 13 1056 a 14 1113 a 18 1101a 14 1053 a 16 113 6 a

17 1070

19 1220 a

Sample 12 (Light wear) ; tested wet

Front Back

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

10 107 0 a 2 1184 a 11 1062 a 9 1174 a 12 1113 a 15 1163 a

13 1107 a 16 1192

14 llll a 17 1113 a 18 1165a

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 861 6 1134 a

4 1089 a 8 1165 a

5 1040 10 1095 a

7 1062 a 14 1160 a

9 1097 a 16 1192

11 982 17 1138a

12 1085 a 13 1097 a 15 964

aUsed to calculate V^q ballistic limit.

23
Sample 13 (heavy wear) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

5 1103 a 4 1158 a 5 1210 a 3 1143

7 1124a 6 1186 a 6 113 0 a 4 1103 a

8 871 9 1165 11 1085 a 7 1126 a 12 1064 11 1165 a 14 1128 a 8 1172

13 978 16 1235 17 1073 9 1138

14 1147 a 17 117 0 a 10 1163

15 1087 19 1215 12 1156

18 1222 a 13 1132 a 15 1117 a 18 1186

19 1143

20 1174

Sample 17 (heavy wear) ? tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

3 1089 a 7 1285 6 1107 a 3 1266

4 1119 a 12 1232 11 1040a 4 1245

6 1132 a 13 1192 a 13 1007 5 1220

8 1107 a 14 1192 a 14 1058 a 7 1210

9 840 15 1215 17 1022 a 8 1083 a 10 722 16 1154 a 18 1079 a 9 1220

11 867 18 1186 a 19 1003 10 1149

17 1163 a 20 1200 a 12 1 103 a 19 1071 15 1130a 16 1068 a 20 1062 a

aUsed to calculate V,-q ballistic limit.

24
Sample 18 (heavy wear) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Average

Round velocity

no. (ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

5 1097 a 3 1109 a 3 1060 a 5 1079 a

6 1034 a 4 1122 a 4 1066 a 6 1097 a

9 103 l a 7 113 0 a 7 1008 a 8 107 0 a 11 997 8 1099 a 10 1097 a 9 1062 a 12 102 0 a 10 1014 a 11 1073 a 13 1130 a

14 1089 a 13 1154 12 995

Sample 22 (unused) ? tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

3 1073 6 1261 3 1156a 5 1192 a

4 1047 8 117 6 a 4 1077 7 1261a

5 1103 a 12 1120 a 6 1195 a 10 1224 a

7 992 13 12 12 a 8 1058 11 1149 a

9 1132 a 14 1227 a 9 1238 a 15 12 18 a 10 934 19 1192 a 12 1099

11 1079 13 1149 a 15 1085 14 1111

16 1132 a 16 1149 a 17 1089

18 1117 a 20 1147 a

aUsed to calculate V

5Q

ballistic limit.

25
Sample 23/24 (unused) ; tested dry

Partial

penetration

Average

Round velocity

no. (ft/s)

(23)

Complete

penetration

Average

Round velocity

no. (ft/s)

Partial

penetration

Average

Round velocity

no. (ft/s)

(24)

Complete

penetration

Average

Round velocity

no. (ft/s)

3 950 4 1255 4 1017 a 3 1117

9 1062a 5 1119 5 1029 a 7 1036 a 10 958 6 1034 a 6 971 8 1049 a 11 104 5 a 7 1122 9 970 10 104 5 a 14 1007 a 8 988 a 14 965 11 1083 a 16 948 12 1047 a 16 1053 a 12 1107 a 17 992 a 13 1002 a 17 1079 a 13 1156

18 1083 a 15 1095 a 18 1005 a 15 1245

Sample 30 (medium wear) ; tested wet

Front Back

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

5 108 l a 3 1113 a

6 1105a 4 1156

8 1163 a 7 1081

9 1165 a 10 1230

14 940 11 1184

17 1083 a 12 1138 a 13 1093 a 15 1152 a 16 1105 a

aUsed to calculate V

5Q

ballistic limit.

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

5 1134 a 3 1134 a

7 1138 a 4 1093 a

8 992 6 1085

11 1128 a 9 1210

13 1073 a 10 1130a 14 982 12 1172 a 16 914 15 1176 a 17 1056 a

26
Sample 31 (heavy wear) ; tested dry

Front

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no. (ft/s) no. (ft/s)

3 1134 a 9 1215

4 1002 10 1099 a

5 1174 a 11 1224

6 1097 a 13 1060 a

7 1122 a 15 1165 a

8 1105 a 17 1172 a

12 998 18 118 l a

14 1147

16 1034

Sample 3 3 (L:

Front

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no

(ft/s) no. (ft/s)

3 977 6 113 0 a

4 1068 a 11 1091a

5 1031 14 1124 a

7 1087 a 15 1062 a

8 1181 a 17 1138 a

9 861

10 1056 a

12 1101a

13 1005

16 1027

aUsed to calculate V^q ballistic limit.

Back

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no. (ft/s) no

(ft/s)

4 1120 a 6 1271

5 1093 a 8 1280

7 12 08 a 9 1261

10 958 11 1245

15 1075 12 1195 a 16 1154 a 13 118 l a 22 1010 14 1240

17 1230

18 1240

19 113 6 a 20 1132 a 21 1299

wear) ; tested dry

Back

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no. (ft/s) no. (ft/s)

3 1167 a 7 12 00a

4 1056 8 1183 a

5 1073 10 lllla

6 1122 a 14 1220

9 998 19 1152 a 11 1042 22 1210

12 107 5 a 23 1130 a 13 1064

15 1031

16 1012

17 1044

18 1126 a 20 1089 a 21 1053

27
APPENDIX B

V^q Ballistic Limit Test Data

Seven Layer Kevlar Soft Body Armor

22 Caliber, 40 Grain, Lead Round Nose Projectile

28
Sample 2 (unused) ; tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 1163 a 4 1227 a 3 1200 a 8 1316

6 1170a 5 1210 a 4 117 0 a 10 1266 a

9 lllla 7 1186 a 5 1224 11 1222 a 10 1085 8 1165a 6 1141a 12 1188 a 11 1202 a 12 1178 a 7 1238 a 14 1220 a 14 1178 a 13 1190 9 1310 15 1212 a 13 117 6 a

Sample 3 (unused) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 1130 5 1208 a 5 1156 a 3 1238

4 1165 a 6 1198 a 7 1158 a 4 12 02 a

7 1143 a 8 1158 a 8 1195 a 6 1178 a

9 1143 a 10 1184 a 13 1117 a 9 1202

12 117 6 a 11 1152 a 14 1132 a 10 1190 a 13 1165 a 11 1170 a 12 1143 a

aUsed to calculate V^q ballistic limit.

29
Sample 3 (unused) ; retested dry

Front Back

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

16 1017 14 117 6 a

17 1068a 15 1145 a

18 1066a 19 1154 a 22 107 0 a 20 1109 a 23 1066 a 21 1085 a 24 108 5 a

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

15 1158 a 16 12 02 a 17 1163 a 18 1280

19 1181a 21 1232 a 20 1220a 22 1220a 26 1117 a 23 12 18 a 25 1170 a

Sample 6 (heavy wear) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 1024 1 1054 a 3 1099 5 1288

4 1007 2 1049 a 4 1132 a 6 1250

5 108 3 a 12 1089 a 7 1172 a 9 1230

6 107 5 a 14 1109 a 8 1230 10 1202 a

7 109 l a 15 1060 a 15 1051 11 1208

8 1051 17 1113 a 12 1208

9 107 0 a 19 1081 13 1181 a 11 1066 a 20 1124 a 14 1 1 1

5

a 13 1062 18 1 122 a

Note: Shot 10, no velocity reading.

aUsed to calculate V

5Q

ballistic limit.

30
Sample 6 (heavy wear) ; retested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

16 1099 17 1158 a 25 1040 21 1143 a 18 1170 a 19 1240 a 26 1062 22 1163 a 20 1149 a 22 1190 a 27 1085 a 23 1202

21 1145 a 24 12 05 a 28 1068 a 24 1178 a 23 1167 a 25 12 08 a 29 1138 a 31 1158 a 26 1192 a 30 1165 a

Sample 7 (moderate wear) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

9 1071 3 1296 6 1186 a 3 1250 a 10 114 3 a 4 1274 7 1200 a 4 12 3 0 a 11 1124 5 1248 a 8 1250 a 5 1176

12 1154 a 6 12 3 5 a 9 1250 a 11 12 99 a 14 1152 a 7 1184 a 10 1261 a 12 1290 a 16 1149 a 8 1154 a 13 1293 a

18 1156 a 13 1357

15 1282

17 12 58 a

aUsed to calculate ballistic limit.

31
Sample 8 (heavy wear) ; tested dry

Front Back

Partial Complete

penetration penetration

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 112 6 a 7 1327

4 1134 a 8 1268

5 1186a 9 124 5 a

6 12 15 a 10 12 3 2 a 11 1222 a 12 12 4 5 a

13 1220 a

14 117 6 a

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

3 1200 a 6 1205 a

4 1220 a 7 12 15 a

5 1172 11 12 15 a

8 1210 a 12 12 2 0 a

9 118 l a 13 1195a 10 1186a

Sample 9 (heavy wear) ; tested wet

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

4 117 6 a 3 1154 a 4 1147 a 3 1174

7 1158a 5 12 02 a 9 104 9 a 5 1170

8 1181 a 6 1165 11 1107 a 6 1145

10 1174 a 9 117 0 a 13 1101 a 7 1113 a 12 1165 a 11 1188 a 15 1000 8 1105

13 1202 16 109 3 a 10 1075a 14 1258 a 12 1119 a 14 1085a 16 1093 a

aUsed to calculate V

5Q ballistic limit.

32
Sample 9 (heavy wear) ; retested dry

Front Back

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

16 1134 a 15 1188 a

17 1192 a 19 1215 a

18 1198 a 20 1195a

22 1149 a 21 1160 a 23 1174 a 24 1227 a

Partial Complete

penetration penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

18 1178 a 17 1200

22 1138 a 19 1186 a 23 1140 a 20 117 6 a 26 113 0 a 21 1136 a 27 1143 a 24 1156 a 25 1156 a

Sample 15 (Light wear) ? tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

8 1128 4 1313 3 1186 a 5 1285

9 1205 a 5 1310 4 12 02 a 6 1364

10 118 l a 6 1277 7 1280a 8 13 10 a 12 1186 7 1230a 10 1290a 9 1299 a 13 1215 a 11 1230 a 14 1245 a 11 1333

15 1190 a 14 1261 a 12 1261a 19 1220 a 16 1277 13 1304 a 17 1220 a 15 1293 a

18 1240 a

aUsed to calculate V^q ballistic limit.

33
Sample 20 (heavy wear) ; tested dry

Front

Partial

penetration

Complete

penetration

Average

Round velocity Round

Average

velocity

no. (ft/s) no. (ft/s)

3 1220 4 1232

8 1109 a 5 1232 a

9 1149 6 12 08 a 10 1126 7 1145 a

12 1134 a 11 1160 a

13 1134 a 14 12 08 a 15 1147 a

Sample 21 (light

Front

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no

.

(ft/s) no. (ft/s)

3 1077 6 1242 a

4 1160 a 10 1232 a

5 12 3 2 a 11 1248 a

7 1222 12 1252

8 1235 13 1222 a

9 1242 a 14 1198 a 15 1174 a 16 1188 a

Back

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no. (ft/s) no. (ft/s)

4 1147 a 3 1174 a

5 1174 a 6 1178 a

8 1160 a 7 1195 a

9 117 0 a 10 1198 a 12 1147 a 11 1172 a

,r) ; tested wet

Back

Partial Complete

penetration penetration

Average Average

Round velocity Round velocity

no. (ft/s) no. (ft/s)

3 1220 a 8 1268 a

4 1250 10 1261 a

5 1238 12 124 0 a

6 1261 14 1242

7 12 32 a 16 1327

9 1248 a 17 1224

11 1232 18 1264 a 13 1224 a 19 1252 a 15 1198

20 118 l a

aUsed to calculate V

5Q ballistic limit.

34
Sample 25 (unused) ; tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

4 1212 a 3 12 12 a 6 1130 3 1258 a

7 12 08 a 5 1188 7 1113 4 1184 a 11 1245 a 6 1242 8 1174a 5 117 6 a 15 117 0 a 8 1304 9 1230a 12 1218 a 18 1122 a 9 1261 10 1198a 14 1282 a 10 1250 11 1198 a

12 12 02 a 13 12 55 a

13 1190a

14 1238 a 16 1277

17 1174 a

Sample 26/27 (unused) ; tested wet

Front (27) Back (26)

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

5 1174 a 4 1285a 3 1222 a 5 1313 a

6 1238 a 7 1268 a 4 1252 a 7 1285 a 11 1172 a 8 1186 a 6 1282 a 8 1238 a 12 1186 a 9 1248 a 9 1242 a 10 1222

13 1188 a 10 1160 a 11 1288 a 13 1248 a 14 1232 a

aUsed to calculate ballistic limit.

35
Sample 32 (moderate wear) ; tested dry

Front Back

Partial

penetration

Complete

penetration

Partial

penetration

Complete

penetration

Round

no.

Average

velocity

(ft/s)

Round

no

.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

Round

no.

Average

velocity

(ft/s)

4 1200 a 3 1266 a 5 12 58 a 3 1318

5 12 68 a 6 1250 a 7 1248 a 4 1242

7 1232 a 8 12 61a 10 1245 a 6 1290

11 12 15 a 9 12 15a 15 1227 a 8 1242

12 12 10 a 10 1258 a 20 1178 a 9 1232 a 12 1261a 13 1266

14 1235 a 16 1245

17 1224 a 18 1198 a 19 1192 a

aUsed to calculate V

5Q

ballistic limit.

36
NBS-114A (rev. 2-80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 86-3444

2. Performing Organ. Report No. 3. Publ ication Date September 1986

4. TITLE AND SUBTITLE

Ballistic Tests of Used Soft Body Armor

5. AUTHOR(S)

Daniel E. Frank; 702

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City. State. ZIP)

National Institute of Justice

U.S. Department of Justice

Washington, DC 20531

10. SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bliography or literature survey, mention it here) A sample of 24 ballistic resistant undergarments (soft body

armor) from a production lot of 1500 originally distributed to 15

police departments throughout the United States in 1975 for issue to

officers as part of a Law Enforcement Assistance Administration

demonstration project, was tested for V

5Q ballistic limit. The

program was a joint effort of the U.S. Department of Justice National

Institute of Justice and the National Research Council of Canada

Public Safety Project Office. Tests of ballistic limit were conducted

on virgin armor that were never issued, and armor showing evidence of

light, moderate, and heavy wear both dry and while wet. The results

show that armor does not lose ballistic efficiency as a consequence of

age

.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) ballistic limit; ballistic-resistant body armor; ballistic testing;

body armor; Kevlar; soft body armor

13. AVAILABILITY

[yl Unlimited

| | For Official Distribution. Do Not Release to NTIS

~~1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

(XJ Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

44

15. Price

$ 9.95

USCOMM-DC 6043-P80