Historical Document · 1959
The Operations Research Office's report on the SALVO I rifle field experiment run at Fort Benning in June and July 1956, published June 1959. The Hyper-Burst Mechanisms dive cites it for the measured hit rates of salvo and burst fire.
UNCLASSIFIED AD NUMBER AD304321 CLASSIFICATION CHANGES TO: FROM: UNCLASSIFIED CONFIDENTIAL LIMITATION CHANGES TO: Approved for public release; distribution is unlimited. FROM: Distribution authorized to U.S. Gov't. agencies and their contractors; Administrative/Operational Use; JUN 1959. Other requests shall be referred to Office of the Chief of Research and Development (Army), Washington, DC 20310. AUTHORITY OCRD, D/A ltr dtd 15 Mar 1973 OCRD, D/A ltr dtd 15 Mar 1973 THIS PAGE IS UNCLASSIFIED CCnrRV'L ONLY Reproduced by nned (e;-vices Technical Information Agency AillI.'WWll HALL STATION j ARLINGTON 12 VIRGINIA 1 *$8R$k '•' ,4" • "NOTICF: When Government or other drawings, specifications or other data are used for any purpose other than J*t crmnettaor with a definitely related Government procurement cy nation, ihe U.S. Government thereby incurs no responsibility, mr my obligation whatsoever^ and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications or other data is not to be regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission to manufacture, use or fell any patented invention that may in any way be related thereto.1 III FfilDI BLANK PAGES IN THIS DOCUMENT WERE NOT FILMED CONFIDENTIAL WORKING PAPER This is a working paper of members of the technical staff of the Tactics Di.ision concerned with ORO Study 11.3. The objective of the study is to develop and exploit criteria for improving the infantry weapons system in a manner consistent with trends in infantry weapons development, organization,tactics, and doctrine. This paper,ORO-T-37«, deals with one aspect of the study. The findings and analysis of this paper are subject to revision as may be required bv new facts or by modification of basic assumptions. Comments and criticism of the contents are invited. Remarks should be addressed to: The Director Operations Research Office The Johns Hopkins University 6935 Arlington Road Bethesda, Maryland ) CONFIDENTIAL COiJFiDENTiÄi AD 304321 TACTICS DIVISION Technical Memorandum ORO-T-378 Published June 1959 SALVO i Rifie R#W Experiment (u) Leon Feldman J. David Rood Joseph W. Hazell Richard E Tille/ William V. Walton Paul F. Michel son Kenneth L. Yi»dowitch William C. Pettijohn Operations Rm search Office and Systems Analysis Corporation OPEKATIONS RESEARCH OFFICE The Johni Hopkias University CONFIDENTIAL Betfcesds, MsryUad CONilBEMflAL • FOREWORD / The members 01 the field team that conducted the experiment, ncluding authors, were George Blaktmore, Ralph Disney, Carl Henslev, Duncan Love.Paul kHcheisen William Pettijohn, Robert Redlck, Kenneth Simpson, William Wat*on, John Young, and Kenneth JCudowttch, ORO, Thorn.-»© C»'~at). Lloyd Corbett, Paui #choltx,and JHTI äümaou, Sprmgiielti Ar xiory; Arthur Burns, Olir. Mütiiieson C.&enuicai Corporation; Cipt #. C. Sclanick, 1st Lts James CooV and «Jridy Dowtin, 2d Lt OÜV** H'-dges, 3d Div, US Array; I-avid Fcrrin, Aberdeen Proving G-c »id, and Charles Dickey. Frankford Arsenal. The data reduction from target faces and electrical recorder tapes were made bv 0*K> research aides Sheldon Cfctoia, Betty Foster Casi Hi iaiey, and Kenr.f -h Simpson. tars. Foster in particular devoted much time to painstaking d?.ta examination and computations. In addition to these participants the authors are Indebted to numerous others within and without ORO for aid of diverse sorts. CONFIDENTIAL CONFIDENTIAL CONTENTS FOREWORD y SUMMARY 1 PHOBLEM—FACTS—DISCUSSION —MAJOR CONCLUSIONS—RECOMMENDATIONS PURPOSE 1 HISTORY 7 SALVO EFFECTIVENESS 13 AMMUNITIONS TESTED 15 TEST SYSTEM 17 INSTRUMENTATION 22 PREDICTIONS 23 DATA . 24 STATISTICAL ANALYSIS 26 SEPARATION OF EFFECTS 27 MISCELLANEOUS EFFECTS B INTERPRETATION 30 CONCLUSIONS tt MAJOR CONCLUSIONS- DRKUSSON or MAJOR CONCLUSWWS—ADOTTTONAI rrmcLvmm RECOMMENDATIONS 42 REFERENCES 373 CONFIDENTIAL CONFIDENT!* APPENDIXES 45 53 A. PERSONNEL B WEAPONS AND AMMUNITION C. TARGET SYSTEM D INSTRUMENTATION E DATA RECORDED F DATA ADJUSTMENT G SQUAD AND QUALIFICATION EFFECTS H I .EARNING 1 RATE OF FIRE J STATISTICAL ANALYSIS K. SEPARATION OF EFFECTS L. EXPERIMENTAL DESIGN M Hrr PREDICTIONS N. MALFUNCTIONS 0. OVERKILL AND PENETRATION P TARCET CHARACTERISTIC EFFECTS 67 115 145 169 205 217 223 231 283 295 311 341 351 359 FIGURES 1. AVERAGE SALVO GAINS 2 1862 SALVO PATENT 3. 1879 OMDNANCE CORPS SALVO 4 1945 NAZI SALVO 5. NAZI SALVO TEST TARGET 6. PROB ABILITY OF FIRING AT, SEEING, OR JITTING TARGET AT RANGE R OR GREATER 7. EAILY PREDICTED SALVO EFFECT OF NOUNDINC WITH 30-CAL RIFLE 8 DUPLEX AND TRIPLEX CARTRIDGES 9. TEST AMMUNITIONS 10 BLANE-RRE RIFLE AND TARGET 11 F (PHONE) TARGET IN UF POSITION 12. FIRING LINE SHOWING STTTINC POSITION WITH ELBOW REST 13 DAY TARGET LAYOUT 14 COMPLETE FIELD LAYOUT VJ. C/S AS A FUNCTION OF ACCUIACY (FULL RAW.*- or PROBABILITY) 16 3 9 9 10 10 11 11 14 14 17 18 18 20 21 38 C/S AS A FUNCTION OF ACCUIACY 40 17. C/T AS A FUNCTION OF ACCURACY 18 C/W AS A FUNCTION OF ACCUIACY 40 40 TABLES 1. OVER-ALL PERCENTAGE CASUALTY GAINS 2. WEAPONS AND AMMUNITIONS TESTED IN THE SAI.VU I KXPERIMENT 3. TARGET CHAR ACT TRBTKS 4 SALVO I TARCET SYSTEM LAYOUT 5. TROOP CHARACTEHBTKS 6 ONE OAVS RUNS 7. TABULATION or R INS (1-68) WITH SQUADS (A-F) AND CONDITIONS SHOWN 8 RATIOS or INMVIDIAL SQUADS TO ABC!) AVERAGE 9 RATIOS or RTFICTIV NUB or DUPLEX, TRIPLEX, AND FLECSTTTF AMMUNrnoM TO SO»CLE-RULLET AjtWUNTTlON 2 15 16 16 19 21 28 28 10 RATIOS or ErrEcrrvcNniior AUTOMATIC TO SOIAUTOMATIC KIR» Till CONFIDENTIAL H CöfiFiDtmiÄl 11. RATIOS OF EFFECTIVENESS OF T48 AND CARBINE TO M1 12. ROUGH GROUPED COMPARISONS H. CASUALTIES BY AMMUNITK)NS AND CONDITION 14. AMMUNITION, SYSTEM, COMBAT LOAD, AND MAN-A?.D-I DAD WEIGHTS 15. CASUALTIES PER SALVO, PER JAKUTE, AND PER RMJND 28 28 30 31 32 16. /tafrflM CASUALTY RATK>S 33 17. UNAIMED-FIRE CASUALTY RATIOS 18. OVER-ALL CASUALTY RATIOS 19 MEAN CRITERION CASUALTY RATKOS 20. PERFECT ACCURACY CASUALTY RATIOS 33 34 35 38 -;i IX CONFIDENTIAL I COiftfMiNTlM PROBLEM To determine the relative effectiveness of multiple-bullet and sLiglebullet rifle ammunitions. FACTS Earlier ORO study indicated that combat rif's fire would be more effective if hits were increased by causing each trigger pull to fire several bullets (salvo pri «K<ple). Ammunition designed to fire in this fashion had been fat ricated. DISCUSSION An experiment designed to compare the salvo cartridges with conventional ammunition in combat-jimulating aimed rifle fire, was conducted by ORO in June and July 1956 at Fort Banning, Ga., under the^ auspices of the SALVO Steering Committee set up by the Chief of Orcnance. The ammunitions tested include .30-cal duplex and triplex rounds (two and three tandem bullets), compared in hits scored against standard singlebullet AP M2 ammunition. Two "minimum-climb" fully automatic .22-cal (single-bullet) types of fire were also tested: the Gustafson carbine and a modified T48 rifle. Automatic burst fire from these weapons was compared with semiautomatic fire Irom the same weapons. A 32-flechette 'oad was also iired from a 12-gage semiautomatic shotgun. These eight types of fire were tested on a combat-simulating range of 22 pop-up (Cocky Ken) targets. Several 10-man groups of firers were used in fitting and standing position, in day and night fire. The experimental data include the number of rounds fired by each man and the number of hits scored on each target. In idditlon, electrical recording provided chronological firing and hit record* by man and target, identifying multiple hitc from the salvo ammunitions. The data were subjected to statistical analysis to determine average values of hit probabilities and statistical reliabilities. The analysis, incorporating factors of lethality and weight, leads to conclusions expre**«4 in casualties per salvo, per time unit, and per weight unit for both aimed and unaimed rifle fire. The hit measures were converted to casualty measures, including account of penetration failure and multiple-hit overkilling. Differences are noted in Ixrth hits and rate of fire as functions of other experimental variables: firing position, Illumination, marksmanship qualification, learning, and target characteristics (size, range, concealment, exposure time, firing activity, and it). ORO-T-171 CONFIDENTIAL CONFIDENTIAL SUMMARY Findings The major findings are summarized In Table 1, which shows the percentages of gain or loss in casualties per salvo (per trigger pull), casualties per time unit, and casualties per weight unit. The six major ammunition comparisons are summarized in this table. The first three lines compare true salvos with single bullets, the fourth line com »ares automatic bursts with semiautomatic bursts, and tne last two lines compare te3t weapons. "Single" refers to regular Ml fire. The comparison of automatic and semiautomatic fire comTABLE i OVöI.ALL PERCENTAGE CASUALTY GAINS« 1 Caeaaltie* time Caaaa » tea/weight •Average' Caaualtiee aalvo unit «ait «a in Ananaaitioa or (trine compared Dap lex to aiagie Triplex to eing!»° + 60 • 110 Flechettee to aiagie b + 290 + 60 • 70 + 100 + 60 + 110 • 200 Aatotaatic to aemiaatomaticc • 60 + 10 - 30 .22-cal carbibe to 30-cal Ml • 10 • 30 • 22-cal T48 to .30-cal Ml • 10 + 20 + 120 + 30 + 60 • 100 »an 4 10 + SO + *> 2a + «i — ±11 ±25 1 5 2 8 t 6 •Over thoae fron .30-cal aingle balle to or eeaiiaetomatic lira. bRaaed on limited dato. c Iacl«dea both Geatafaon carbine «ad modified T48 rifle. * bines both carbine and T48 results, since they are nearly identical. The carbine and T48 are compared with the Ml in semiautomatic fire only. The "Casualties/time unit" Incorporate experimental data on rate of fire. The "Casualties/weight unit" are baaed on the weight of the weapon plus normal ammunition load (224 rounds). Table 1 Is deduced by weighting the (Ijree firing conditions hi the approximate ratio of the amount of experimental firing— 2 (day sitting): 1 (day standing): 1 (night sitting). This ratio la extremely i onservatlve in heavily weighting the moat accurate firing condition. Secondly, -alues are derived for unalmed-flre casualties. It la noted that the experiment measured only almid fire. However, the arbitrary over-all estimate shown is thought l be the better general effectlveasee measure. The oaa**^etf "CaauaJV«/salvo" la simply the product of the number of bullets par salvo and the lathality per bullet, adjusted for penetration failure and multiple-hit overkill. The table combiaee the Averages for aimed and unalmed fire on a fifty-fifty basis. The value of thie »mitmed fire la it» neutralising or haraaaaag effect le a^um^tohemeaeurtdbyiw casualty Tat fifth single effect! r roluaam "Average gala/ la a crude method of a ratio, ft la simply aa average of the CONfflMNTIAl ig a rough riteriaof the COäSrSDEMTIAL IB FifEtfB i >»ws the average values, together with the 95 percent <:o»Jlderwx 'za-li TSal confidence limits (2 a) estimate (with a 95 percent certainty) the range within which the true gain lies. For example, with a 95 percent certainty it is known that the average duplex over single-bullet effectiveness gain (as defined) is between 53 percent and 67 percent. These limits are deduced from sampling errors only. Systematic errors are found to be up to two to three time« larger. DUPLEX TRIPLEX FLECHETTE AUTOMATIC CARBINE T48 100 ISO CAIN, % Fig. 1 —Av»rag« Salvo Gains L*w*r cftnf id*nc* limit . »»«ro«« UpfMf c*nli4«nc« HmH 95 p«rc*nt cami<i«nc« be tdt MAJOR CONCLUSIONS if. All salvo ammunitions examined show effectiveness increases. The 60 percent duplex cam is unequivocal; the automatic fire gain is smaller, depending on the criterion selected; and the triplex and flechette gains of 100 and 200 percent require further verification. jr. The smaller weapons examined show effectiveness increases of 20 to 50 percent over the Ml in conventional semiautomatic fire. $/ Typical fire is at a rate of 16 rounds/min after lV« sec to acquire at target. Average test accuracy Is 14 percent hit probability, or an error (linear standard deviation) of 3.8 mils. OR0-T-J7B CONFIDCmiAL CONFIDENTIAL ARY •P RECOMMENDATIONS From these conclusions and the discussion accompanying the 22 conclusive in the body of this memorandum, the following recommendations are deduced: 1. The duplex and triplex ammunitions should be considered for adoption. 2. Additional tests of triplex and flechette ammunitions should be conducted. 3. Flechette development should be accelerated. 4. A flechette side-arm load should be developed for test. 5. Doctrine for aimed - ctomatic shoulder fire should be reviewed. 8. An investigation o! smaller weapons should be initiated to identify observed .22-cal gains. 7. A .22-cal duplex ammunition should be fabricated and tested. 8. The peep-sight requirement should be reconsidered. 9. Actual combat accuracy of rifle fire should be determined. 10. This experimental context should be considered for training use. • ORO-T-378 CONFIDENTIAL CONFIDENTIAL SALVO I RIFLE FIELD EXPERIMENT CONFIDENTIAL CONFIDENTIAL PURPOSE To determine the relative effectiveness of multiple «bullet and single billet rifle ammunitions. An experiment was performed to determine hit probabilities with salvo ammunitions in combat-simulating aimed rifle fire. The analysis, incorporating factors of lethality and weight, leads to conclusions expressed in casualties per salve, per time unit, and per weight unit for aimed and unaimed rifle 'ire. HISTORY The salvo concept is by no means new. Probably some clever caveman put several atones in his sling at one time. Stories exist describing the practice of some tribes in early modern warfare who used knives to split their lead bullets. The shotgun is an example of extreme salvo, where lethality and range capabilities have been compromised for the hit increase in the projection of multiple pellets. The massing of artille: > fire is a further example of salvo, using separated launchers. The machine gun and the automatic rifle approximate the fundamental characteristic of salvo, which if the projection of more than 1 round with a single aiming and firing effort. The type of salvo development with which this paper is concerned appears in the 1856 US Army Ordnance Report.1 This report describes fire of two and three round b*'l9 at one time from a "rifle musket." An 1862 US Patent* describes "Improvement in Compound Bullets for Small-Arms" (Fig. 2). Official concern appears in the 1879 Ordnance Report to the Secretary of War.1 That report includes the disclosure and subsequent correspondence of Captain of Ordnance E. M. Wright, who proposed the use of a U?ndem salvo round—three bullets nose-to-tail in a single cartridge (Fig. 3). Captain Wright's efforts were defeated by Captain of Ordnance J. E. Greer, whose negative report was indorsed by the Chief of Ordnance. An overshadowing development, the introduction of the magazine rifle, squelched further efforts at that time. In early 1945 the Naiie reported on "Die Infanterie Doppelgeschosz."4 Their report describes in detail the development and testing of a tandem duplex rifle round and several modifications (Fig. 4). The German reports indicate considerable success (Fty. 5) and plans for special issue in 1945 as is indicated by the following: PROGRESS REPORT NO. «4 17 March 1945 On the Presentation of the D-Ammunition ard Discussion at Friedenthr' on 17 March 1945 OTO-T-J7I CONFIDENTIAL I CONFIDENTIAL Suhlest* Hue of D-Ammunition for Special Issue (SS-Assault groups) The purpose of (fee ?resentatlcu In Finow wan to issue the D-Ammunition to the battle front. S3 Sta^j U»*»us»«r r>r Heesa propos**«» ü Si *hl» new type of Infantry ammucU'on be f* 2t Icsaed to the Paratreep assault groups b9c*?«*>e i- -JS nnasible to obtain an tarly u»,*ic#i rr" •* >o !. *«i be Uept 100% secret S3 ri ;•«•• «, „±rdt suggested that ?2 UrfiJi «iohurmann take part la the tests at VSaoar. The development of D-Ammunition for the Pistol 08 and the Infintry S*urm rifle Is also as urgent as for this caliber. ORO analysts, examining the operational concept of small-a rms aimed fire, recomme ^tv. La 1952* the development of a weapon designed to fire sim ' taneously up to ii:\- ojte. tiles: 1. It is recomu-: r* '" that iüo Ordnance Corps proceed to determin > '.ne .ic«i«rn or technological feasibility ot developing a hand weapon which has the characteristics cited in this analysis, namely: a. Maximum hit effectiveness againt.t man targets within 300-yd range fFig. 6]. (This does not mean that the weapon will be ineffective beyond Ulis range.) b. Small caliber (less than .30). c. Wounding capability up to 300 yd at least equivalent to the present rifls. d. Dispersion of rounds from salvos or bursts controlled so as to form a pattern such that aiming errors up to 300 yd will be partly compensated, and hit effectiveness thereby increased for these ranges. 2. As one possible alternative to the current volume of fire (fully automatic) approach to the problem of Increasing the effective firepower of infantry riflemen, it is recommended—subject to tractive confirmation of design feasibility—that a rifle incorporating at least in principle the military characteristics here proposed be manufactured for further and conclusive test. This concept was presented by ORO to the US Array Chief of Staff, Gen Lawton A. Collins, who directed Ordnance to develop materiel to evaluate the proposed concept. In response to this order, the SALVO Steering Committee was formed, in 1953, ORO published a memorandum* describing the theoretical performance of duplex and triplex tandem rounds (Fig. 7). Subsequent industrial development and testing of these tandem rounds proceeded under the direction of the SALVO Steering Committee. In 1954, ORO, in response to a request from the SALVO Steering Committee, designed a field experiment to determine the hit probability of the ta idem salvo round in aimed combat rifle lire. By 1956. coordination efforts with ballistic Research Laboratories (BRL) (teeAppL) and other interested agencies permitted acceptance of the ORO test plan and assignment of facilities at Fort Benning.* In June 1956 the experiment wa& conducted by ORO. The recommendations of this memorandum are essentially the same as the preliminary recomir. ?ndatlons presented in an earlier report." These conclusions and recommendations have already been disseminated, and in some part carried out. At this writing, duplex ammunition is being procured for official user test with both Ml and T14 rifles. A program is under way (with apparently inadequate priority, however) to examine the shotgun flechette Improvement witli reduced dispersion. A recommended development of a flechette side-arm or pistol load Is currently In the doldrums, but several agencies are interested m supporting the development. OHO-T-I7I CONFIDENTIAL CONFIDENTIAL UNITED STATES PARENT UmcK* r, 4ft» aäfc W. MUUttl, or MllbM mALMA, Off ILtt, 9TBV i Ä^SeVi5SS«T •» COS**»*« »** ÜtAkL-All Wfci. ***• *v- %* ^ ^p A. f> A' fli* *£•* *%* /%•*• n* Fig. 2-1162 Salvo Patent DESCRIPTION Or 1U0KBBOT OABTRIDGB, rOB PBB8BNT SBRYICK ARMS A.HD 1LTVKED MBY0L7BB&.—CAL. .46 BUCKSHOT. Cum«, preorut rifle NM, aaifonoly Uj* nil; chartf*, 40 or 46 grain* amir* ]K»wd«r; 3 round bullota, pure i*ad: diaairtor, ".450; Inbcirant, l.ullrt« diuprd in Jauava WAX. uiiilrt» punbetl in far efHM^fk to afford % good criBf ca loo* oar. «••r.rt.rr^ % Fio. 3-1179 Ordoonco Corps Solve ORO-T-378 CONFIDENTIAL % % CONFIDENTIAL t*9 o,ssg H-Qeschob 8.15t0,04q Fig. 4--1945 Nazi Salvo Fig. 5—Nazi Sdvo Tttt Torgat 10 ORO-T-37t C0HFIDEN7IAL CONFIDENTIAL Firing at targat ?00 400 RANGE, YD Fig, 6—Probability of Firing at, Sooing, or Hitting T argot at Rang« R or Groator Triplex ammunition / 100 200 '00 400 ftAMOC. YO Fig. 7-Eorly Predict«! Salve Effoct of Wounding with .30-co! RifU ORO-T-S78 U CONFIDENTIAL CONFIDENTIAL Interest in the aaivu rilie program has resulted in the publication of other studies. It is appropriate here to discuss the interpretation of apparent inconsistencies that have been noted. The most pertinent study that has come to the writers' attention has been published by BRL.* A major difference between this BRL report and the present study arises from the effectiveness criterion. The BRL study is based on the criterion of "one or more hits." This criterion discriminates against a salvo load in failing to credit multiple hits with more lethality ti an a single hit. A second assumption is an un realistically low aiming error of only 1 mil (this experiment showed 3.3 mils average daylight error). The BRL coiiciuaiuii thai * ier no consideration is the duplex bullet superior to two independently aimed projectiles* is misleading, since it is true only when based on a quite inequitable criterion: one duplex firing vs two singlebullet firings. Two independently aimed projectiles require two weapons and two men for the same opportunity, or a repetition of the opportunity. The summary tables in the BRL report suggest that the calculations are based on the unrealistic assumption of no holdoff (elevation) for gravitational drop. The need that the BRL report recognizes for theoretical estimates of the effectiveies> of the controlled duplex round was recognized, and a publication was under way simultaneously with the BRL report.19 The BRL criticism that ÖRÖ-SP-2* fails to emphasize the superiority of the .22-cal carbine is accepted. The totality of these criticisms negates the primary BRL conclusion that "the advantages of the duplex round SALVO rifle are marginal." The authors of this memorandum are in agreement with the final statement of the BRL report: "Any promising small arms should be finally evaluated on their mass effectivei ess against anticipated number of men in likely patterns, i.e., under service condition*.* Furthermore the authors believe that this (ORO) memorandum has made a substantial effort to satisfy this condition of evaluation. A second study of direct concern has been made by the Armour Research Foundation (ARF) for the Springfield Armory." This study correctly concludes that the exact form of an optimum salvo has not been determined and is not determLiable without an ambitious program of basic studies. The Armour repoit implies that experimental materiel development on items such as the duplex might best be curtailed, as they do not represent theoretical optimum ammunitions. !.n the light of practical considerations of such matters as lead time, such ar. implication is unwarranted. The practitioner of military art is generally aware that the materiel he accepts in order to maintain a status of preparedness rarely represents the theoretical optimum, and the satisfactory item is accepted instead of waiting for the perfect item. The Armour conclusion that an optimum salvo number exists is in itself very tenuous. Clearly, radically different forms of salvo will yield different optimum numbers, and the criterion for selection among these types will surely transcend the theoretical criteria on which the proposed studies would be based. Dollar and logistical cost and development time are significant items that musi modify any conclusions from a theoretical technical itudy. The specific proposal of Armour for an automatic weapon is of course worthy of separate consideration, provided that the weapon could overcome the obvious disadvantages of automatic fire that are demonstrated in this (ORO) study. Another salvo study has been conducted by the Midwest Research Institute (MRI)." The MRI report conclusion that "the best system uses a M Flechette cartridge" is based on examination of cartridges of 64 or less flechettes. It i:i ORO-T-378 CONFIDENTIAL CONFIDENTIAL • appears that the criterion on which this conclusion is based would yield tue more general conclusion thai üie üesi uaf ü>*r of salvo projectiles» i» U*t s mum number possible. The determinat on of an optimum number requires the application of additional constraints. MRI's conclusion11 concerning the desirable dispersion of flechettes Is in reasonable agreement with a recent study conducted by ORO.1* SALVO EFFECTIVENESS The objective of wiiiiary fire is ettstt to aeutraüäc or to inflict casualties on an enemy. Casualty infliction in turn may be separated by target characteristics into categories designated as aimed fire and unaiiueu fire. The application of the salvo principle to unaimeo area fire is so elementary as not to require specixic field tests at this time. Because area fire targets are characterized by a dispersion in considerable excess of the dispersion of any reasonable salvo, it is clear that the hits are merely proportional to the number of bullets per saivu, ignoring variatious in hit probability or lethality with variations in range or other characteristics of the targets, in the case of automatic fire, the definition of a salvo and the deterioration of aim with succeeding rounds are subjects of separate consideration. The experiment made no attempt to include area fire. The concept of measurable effectiveness of 7*med fire has throe parts. The stated objective of aimed fire, "infliction of casualties on targets," provides identification of the three essential and commensurate elements. To "inflict," the target must be hit with the bullets, implying a measure of hit probability. "Casualties" implies a measure of the casualty-producing effect or lethality of the bullets. Thirdly, "targets" implies that both of the above measures must be applied to the enemy target system that is anticipated. The first two parts of the concept are well recognized. In general, how«v~«r, earlier efforts at relative evaluation of firepower have failed to provide an integrated measure reflecting the anticipated target system. As an operational analysis it would appear to be an incomplete study that provides only a table of potential effectiveness against a list of target types. The authors have attempted herein to make a realistic integration of anticipated target types in order to derive a simply expressed measure of relative effectiveness. Withall, the design retains the capability of correction of these measures with modification of our model of the target system. The potential hit increase of salvo rifle fire depends on the existence of a fairly large error in combat rifle capability. "Combat expenditure of small arms ammunition per hit is prodigious-some 8000 to 12,000 rounds."14 Measures of rifle aiming erro** indicate that under target-range conditions, riflemen achieve errors of less than 1 mil. It is evident, ho\7ever. that typical comoat error is larger. From a preliminary experiment,1* it was estimated that typical combat rifle fire occurs with an error of 3 to 4 mils. This figure is the linear standard deviation (o) of a radially normal distribution, and may be interpreted as an average value. Examination of weapons used in this test indicates the typical dispersion inherent in the weapon—a few tenths of a mil (App B). Exterior ballistic errors for most combat ranges (< 300 yd) are likewise generally ORO-T-37» IS CONFIDENTIAL CONflDENKAL Fig. 8—Duplex and Triplex Cartridges .30-col »ingl* bull** •—J ^m« 1> •30-cal dupUi .30-cal rr.pUx • 22-cal corbin« t it f 22-col T48 32 tische«*« Fig. 9—Test Ammunitions 14 ORO-T-I7I CONFIDENTIAL CONFIDENTIAL much less than 3 cr 4 mils. It is apparent that the human aiming error represents the preponderant Influence among these Independent error sources, desspite contention to the contrary.1' The increase of hit probability then becomes a problem of overcoming the predominant human aiming error. This may be accomplished either by reduction of error, or design of a mode of fire compatible with such an error. No recommendations are made here regarding continuation of efforts to reduce the aiming error by training or by any other method. The approach of this study is restricted to the evaluation of materiel designed to increase the hit capability o? present rifier«*" AMMUNITIONS TESTED The salvo system deemed operational at the time of investigation was the tandem round; which is actually not a salvo weapon, but a salvo ammunition ior Incorporation in conventional small arms, "the primary test item is the duplex, second the triplex (Fig. 3) with single-bullet ammunition for comparison. The f rent duplex bullet maintains dispersion comparable with an ordinary single bullet; the rear bullet of a pair falls in a narrow ring concentric about TABLE 2 WEAPONS AND AMMUNITIONS TESTED IN THE SALVO 1 EXPERIMENT Weapoa Ammunition or firing Muzzle velocity, ft/tec Round weight, greine Bullet weight, grains 2760 2630 2630 3125 3125 3400 3400 1400 414 449 439 135 135 280 290 720 163 96 61 41 41 68 68 13 Ml rifle (reamed chamber) 30-cal single-ballet M2 .30-cal duplex .30-cal triplex .22-cal semiautomatic Gustafs on carbine (M2) .22-cal barst fire .22-cal semiaatosMtic T48 rifle .22-cal burst firs 12-gage autoloading shotgun 32 flechettee the front bullet. The angular spread between the two bullets is the radius of the ring, approximately 3 mils, which is about optimum, being the width of a man-target at combat range.1* Th? .32-cal carbine and the T48 afford two examples of burst (automatic) fire—with semiautomatic fire for comparative controls. These 22-cal weapons were selected as tltose available offering the least climb—the best hold on target for a salvo burst. The 32-flechette load was tested as the moil promising of several flechette developments.1* Figure 9 shows the test ammunitions and nominal characteristics. The measured characteristics are given in Table Bl, App B. Four types of weapon were used, and a total of eight different combinations of weapon and ammunition or types of fire were tested. Tfceee tight combinations are shown in Table 2. ORO-T-aVTt II CONFIMNTMl CONFIDENTIAL TABU: J lAHUKT Oi AH ACT KRIS I1CS Characteristic Amount or type Sis« Haag« Kxpoaure time Visibility Movement E (knee Hng) and F 'proae) 50-350 yd 3 to 34 'i aac Day, night, day-hidden 3 of 22 target« Blanks being fired --' " targnti 20 demolition positions plus a phonograph \. ti.ii» Confusion TABLE 4 SALVO 1 TARGET SYSTEM LAYOUT Target number Haag«, yd Tarnet aiia* (oncealment 1 2 3 4 !> 6 7 8 9 10 11 12 IS 52 63 65 67 74 76 77 78 86 89 90 91 Hi 127 !19 159 161 162 164 165 169 176 209 216 218 F F C — _ C — — 14 15 16 17 18 19 20 21 22 23 24 25 2ft 27 21 20 10 11 12 Ml m m m I F F E F F F F F F F r F E E F E E M sat 14 Taul Rlaak firiag Illamination Expos are time, aec F — — F F F F F — F F _ N N N N D N D 28.5 3.0 7.5 12.0 4.5 4.5 15.0 19.5 4.5 15.0 4.5 9.0 19.5 9.0 4.5 10.5 3.0 6.0 18.0 34.5 4.5 9.0 3.0 4.5 15.0 7.5 21.0 6.0 10.5 3.0 2S.5 7.5 c c — c c — c c — _ — — — c 1 M • M — c r F F F F F E — c c F F _ _ F _ — _ — F _. _ mm — — — — F F F F — — — F — c w %%\ »4 M6 Movement c F F F F c MC 14C 20» F IM 19F N D D N N D-N D-N D-N D-N N D-N D-N D-N D-N D-N D D-N s N D D D D D D 0 10D-N 120 12* M 210 231 00 253.5* •«fFipnMlaaV !• ORO-T-171 (ONIIIENTIAt CONFIDENTIAL TE Jl OlOlIii To describe coinba*. targets in terms of seven characteristics that critically affect aiming erro :• as shown in Table 3, a questionnaire-interview was administered to veteran riflemen (App C). A study of the infoination obtained led to the adoption of two target systems—one for daytime fire and one for nighttime fire. Each ri these systems was composed of 7.2 pop-up (Cocky Ken)1* targets, 10 of which were common to both systems, muting a total of 34. The target* *mr* exposed by coringloaded mechanisms for time durations of 3 to 34% sec. None of the targets was C*ur*Mr mt OHm At—fcfa—n Ofmicmt Cmp. Fig. 10—3lonk-Fire RifU ond Torge! scheduled for exposure simultaneously with another, and the intervals between successive target exposures were varied. The sum of the scheduled exposure times for the 22 targets during a day run was 220 sec, and the total time for the run was 7% min. This means that during a run some target was scheduled for exposure during about half the total time for the run. Tnree of the targets moved laterally during exposure. Target activity was indicated by blank fire at half the target positions (Fig. 10). The 10 firing position» were on a SO-yd firing line. The ranges from the firing line to each of the 34 target positions and other characteristics of these targets are shown in Table 4. Target sines were limited to two: E (kneeling) and F (prone) silhouettes (F shown in Fig. 11). The minimum target lange was limited for safety to 50 yd. The maximum range of 350 yd reflects the occurrence of 95 percent of combat targets within that range (App C). Variations in visibility were limited to three: day, exposed; day, partly concealed; and night, expr.sed. ORO-T-ITt It CON'IMNTIAl CONFIDENTIAL CMMMT * Oil* Ma*J»««i Onmlcml Car», Fig. 11—F (Pront) Torgot in Up Position CM^MT •» 01* iildmiii Ommt—I Cwp. Fig. 12—Firing Lin« Showing Sitting Position with Elbow Root ia rktto T ••»• CONFIDENTIAL CONFIDENTIAL The aiming error also depends OS the rifleman (Table 5). TO make the experiment applicable to typical US riflemen, four average 10-man squads were constituted of riflemen of Qualifications in the same proportion that occurred in the 3d Dlv: one expert, four sharpshooters, four marksmen, and one unqualified. In aldition, one better and one worse squad were tested. The firing positions were limited to two: a stable aiming position, raised enough for all men to see all targets, sitting with elbow rest (Fig. 12); and a poor aiming position, standing. Detonation charges in the target area and recorded battle noises added confusion lor the riflemen. In addition, the riflemen vere subjected to electrical shocks at irregular Intervals during the runs by means of wires attached inside the boot. TABLE 5 TROOP CHARACTERISTICS Qualification Poeition Streee Batter, average, worse Sitting, sundin« Shock and noiae To recapitulate, each target system was then composed of 22 Cocky Ken targets, 3 of whic<> were capable of lateral movement, and 11 of which returned blank fire iFigs. 13 and 14). There were 20 demolition positions, including nltrostarch charges to simulate artillery, and blasting caps, readily confused with rifle fire. So iads were deployed on a 50-yd line. For uniform visibility, night firings were conducted with limited floodlighting. The entire program of target appearances, target movements, demolitions, blank firing* EüU aUr»«* shocks had to oe precisely reproducible for a controlled experiment. To accomplish this, electrical controls were plugged into a specially built programmer before each run. To start a run, it was necessary only to push the starting button; operation was then automatic for T/% min. The entire schedule was composed of 68 runs. Only two runs were allotted to the flechette test, owing to limitation on available ammunition. Each of the other types of fire was scheduled to fire from the sitting position both day and night, and from the standing position in the day (Table 6). Deletion of most of the planned triplex runs was necessitated by a malfunction. The Cocky Ken targets drop on schedule, not widen hit. There were no simultaneous target appearances, and the order of target appearances was varied between runs. Ammunition expenditure was unlimited. Physical details of the test system may be seen from motion pictures taken during the experiment. ORO has prepared a 6-min film showing the installation and operation of the test system. Included are pictures of installation of the electrically operated targets, installation of track for the moving targets, zeroing and familiarization fire of the test *veapons, and a view of the several special devices (stress shockers, shot recorders, and target hit recorders). The films also show fire on targets during runs, revealing the general patterns of fire, and giving a clear picture of the environment of the test. ORO-T-378 19 CONFIDENTIAL CONFIDENTIAL ono- r-sit 20 CONFiptPiTUi CONFIDENTIAL »A* Of MTttVAL. YD P»§. l4-Ownpl*f Fi«ld L.yo* k. blank »•»•, «. »fcntim c«f, 0. »»<!»< OüD-T-Stt COüriHNTiÄL CONFIDENTIAL The test plan, including a summary of requirements drawn up in December 1955, appears as Annex LI to App L. This annex describes the elements behind the questionnaire of App C for determination of the target system, and outlines that system. It also outlines a schedule of firings and a list of the various requirements. In addition, App L discusses the adequacy of this test plan, and points up the considerations favoring it over others. Considerably more detail on the statistical validity of the test plan is given in App M. A master schedule of the actual experimental runs is riven in Table L2. TAW I 6 ONE HAY'S RUNS Run no. ammunition Visibility Position Squad 1 2 Control Tent Control TON Control Te»t Control Tent Day Pay Dsv Oav Dav i).v N'iaht Ni*ht Sitting Sittina Sitting Sittina Stand ins. Standina Sittiaa Sittiaa K \ B H \ * R R i \ 5 6 : 8 INSTRUMENTATION The operation of all targets was controlled by a programmer, which was set before each run by means of a patch board of 300 sockets. Eight different programs for daytime runs and four different programs for nighttime runs were used. The different programs presented the targets in different sequences, but the times of exposure, and the intervals prior to urget exposure after the preceding target dropped, were held constant for a given target. The intervals between target appearances varied from 6 'o 13% **c. For recording shots fired, each test rifle was equipped wiu a specially constructed switch within the trigger mechanism. The switch was closed with eacn trigger pull, which fed impulses to an Esterllne-Angus recorder. Separate channels were used for recording the shots from each of the 10 firing positions. For recording the number of hits, each target silhouette was covered with two sheets of electrically conductive rubber with an insulating rubber sheet sandwiched between them. The passace of a bull »t through the sandwich caused a momentary electrical connection between the conductive rubber sheets. The completion of the electrical circuit between the tw conducting sheets activated a mechanical counter, and also recorded on a continuously advancing roll of paper. The circuitry permitted the separation of hit impulses to about 1 msec, which permitted recognition of multiple hits. It was also possible to Identify shots fired with hits scored. The demolition charges in the target area, and the blank-firing rifles were controlled by the programmer to permit precise pre scheduling OHO-T-37* CONFIDENTIAL CONFIDENTIAL , At each firing position, a i*mcry and hign-voiiage coil were connected to electrodes that could be slipped into the riileman's boot. Under control of the programmer, shocks were delivered to the rifleman to simulate battle stress. The shocks could not exceed lOYi ma in current, but produced jolts of up to 5300 volts. In view of the complexity of the instrumentation for the SALVO I experiment, it is not surprising that many malfunctions occurred. It seems clear that the electrical data should be appropriately adjusted to eliminate the effect of malfunctions as far as possible. Fortunately, many questions of interest can be studied ?jid conclusions reached on the basis of manual counts of ammunition used and holes in target faces. The major portion of the analysis in this paper is on this basis. Investiga' on of hits by