Wound Ballistics: Minié Ball vs. Full Metal Jacketed Bullets A Comparison of Civil War and Spanish-American War Firearms

Transcription

1 MILITARY MEDICINE, 174, 4:403, 2009 Wound Ballistics: Minié Ball vs. Full Metal Jacketed Bullets A Comparison of Civil War and Spanish-American War Firearms Paul Joseph Dougherty, MD * ; MAJ Herbert Collins Eidt, MC USA ABSTRACT Objective: The advent of the full metal jacketed bullet in the late nineteenth century was thought to cause less severe battlefield wounds. This study compares the wounding characteristics of a reproduction rifle from the American Civil War to one of the Spanish-American War using the wound profile method. Methods: A 0.58 caliber rifled musket using Minié balls and a 0.30 caliber Krag-Jorgenson rifle using full metal jacketed bullets were fired into calibrated 10% ordnance gelatin blocks at a distance of 3 meters. Measured parameters included maximum temporary cavity, muzzle velocity, and the permanent track. Results: Maximum temporary cavities were significantly larger using the musket, averaging 121 mm (± 5.4) vs mm (± 8.8) ( p < 0.001). Bullet weights were also significantly larger, totaling 29.7 grams (± 1.3) for the musket vs grams (± 0.01) for the rifle ( p < 0.01). Using grains, bullet weights were grains (±20 grains; range ) vs grains (± 0.15; range ). Muzzle velocities of the musket were significantly less when compared with the rifle, averaging 944 fps (± 116) vs fps (± 22.5), respectively ( p < 0.001). Conclusions: The rifled musket produced more severe wounds when compared to the Krag-Jorgenson rifle, as was clinically apparent to observers at the time of the Spanish-American War. INTRODUCTION The late nineteenth century saw the development of a full metal jacketed bullet as a means to improve military firearms by increasing the range and accuracy over solid lead bullets. The changes in bullet design were also thought to have an effect on the types of wounds seen with battle casualties. When comparing casualties from the American Civil War to the Spanish-American War, observers noted less severe wounds. Borden also noted a decreased reported mortality among hospitalized patients with extremity wounds: from 13.8% to 1.6% (lower extremity) and 6.5% to 0.2% (upper extremity) when comparing casualty statistics of the Civil War to those of the Spanish-American War. 1 Bullet development occurred rapidly in the nineteenth century compared to any other time period. Early nineteenth century weapons were usually smoothbore muskets that fired round lead balls of about 0.50 to 0.75 inches in diameter. Smoothbore muskets were not accurate beyond about 50 yards. Although accuracy could be improved with the use of a rifled barrel, the fit of the bullet/barrel needed to be tight to impart a spin on the projectile. This made reloading too slow for the standard military arm. In the mid 1840s a bullet was developed by Captain Claude E. Minié of France that allowed for practical use of a rifled barrel for the standard military arm. The bullet was cone shaped and had a hollow base that expanded when fired, thus engaging the rifling of a barrel to impart a spin on the bullet to stabilize it in flight. * Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI Winn Army Community Hospital, 1061 Harmon Ave., Fort Stewart, GA This manuscript was received for review in June The revised manuscript was accepted for publication in November This allowed the bullet to be easily loaded from the muzzle, yet created a tight fit to engage rifling when the weapon was fired. The conoid bullets varied in size and weight, but were generally between 0.54 and 0.58 inches and weighed approximately grams ( grains). 2,3 Use of the conoid bullets, or Minié balls, changed the tactics of mid-nineteenth century wars, including the American Civil War. Surgeons also noticed there was increased wounding sometimes seen with Minié balls. 4,5 Otis described the increased destructiveness of the Minié ball when comparing wounds made with Minié balls compared with the older musket ball. 5 In 1881 a full metal jacketed bullet was developed and combined with a bottlenecked cartridge and smokeless powder by Major Rubin, a Swiss Army Ordnance officer. The full metal jacketed bullet of smaller diameter was fired at an increased velocity, allowing it to be more accurate over longer ranges. The wounding effects of the newer full metal jacketed bullets were controversial at the time. Some felt the newer full metal jacketed bullets would cause increased tissue disruption and more severe wounds, 6,7 whereas others felt the wounds would be less severe. 1,8 14 A method of reliably predicting the effects of the projectile-tissue interaction was developed in the 1980s at Letterman Army Institute of Research by using ordnance gelatin. 15,16 This study uses the wound-profile method to compare the wounding effects of two standard infantry shoulder-fired weapons used during the Civil War (Replica Colt 1861 rifled musket firing 0.58-inch Minié balls) and the Spanish-American War (Krag-Jorgenson rifle firing 0.30-inch full metal jacketed bullets). To the authors knowledge, this is the first study that compares representative arms from the two conflicts to document the differences seen. MILITARY MEDICINE, Vol. 174, April

2 MATERIALS AND METHODS Two shoulder-fired weapons, representative of those used in the American Civil War and the Spanish-American War, were compared using the wound-profile method. Firearms used were a replica Colt (Hartford, Connecticut) 1861 rifled musket (0.58 caliber) ( Fig. 1 ) and an original 1895 Krag-Jorgenson rifle (Springfield, Massachusetts) ( Fig. 2 ). Projectiles for the rifled musket were original 3-ring Minié balls ( Fig. 3 ), which were loaded with 60 grains by volume Pyrodex powder (Pyrodex, Hodgen Powder Company, Shawnee Mission, Kansas). Original caliber ammunition (1901 Frankfort Arsenal, Pennsylvania) ( Fig. 4 ) was used for the Krag-Jorgenson rifle. This technique is done by firing shots into 10% ordnance gelatin from a distance of 3 meters. A minimum space of 3 meters is necessary to provide space for the chronograph switches. The ordnance gelatin used in this technique approximates damage seen in soft tissue. Type 250A ordnance gelatin (Knox and Kind, Sioux City, Iowa) was made by adding powder to cold water for a 10% by weight solution The mixture was heated to 39 C, poured into cm molds, and cooled to 4 C. The gelatin was allowed to sit and then was removed from the mold. The gel was ready to use at 36 hours FIGURE 1. Lock for the rifled musket. FIGURE 2. Action for the Krag-Jorgenson rifle, showing the magazine feed for cartridges. FIGURE 3. Unfired (left) and fired 0.58 caliber musket bullets. FIGURE caliber cartridge, cartridge case, and recovered bullet. after pouring. To calibrate blocks of gelatin, a 0.31 gram BB was fired into one corner of the gelatin at feet per second. The BB should penetrate 7 10 centimeters to assure consistency. The calibration was away from the planned shot line and did not interfere with the results. Muzzle velocity, in feet per second (fps), was measured using an Oehler 33 series chronograph (Oehler Instruments, Austin, Texas). Five shots from each weapon were fired into the calibrated ordnance gelatin blocks. Projectiles of the musket were weighed before and after the shots, while the recovered 0.30-caliber projectiles were weighed. The projectile tissue interaction in the gelatin was examined over likely depth of penetration for a thigh (15 cm) to represent a worst-case scenario for an extremity wound. End points measured were permanent and temporary cavity along the bullets path in ordnance gelatin. Permanent cavity was calibrated by measuring the diameter of the projectiles path in gelatin, usually outlined by lubricant or powder as the projectile passes through the gelatin. Temporary cavity is calculated 404 MILITARY MEDICINE, Vol. 174, April 2009

3 by measuring radial splits from the bullet path in the ordnance gelatin. Comparison of data between the Krag-Jorgenson rifle and the rifled musket was made by using the Student s t-test. RESULTS Muzzle velocities of the rifled musket were significantly less when compared with the Krag-Jorgenson rifle, averaging 944 fps (±116; range, ) vs fps (± 22.5; range, ), respectively ( p < 0.001). Maximum permanent tract diameters in the first 15 cm of the musket wound track were significantly greater than the rifle, averaging 16.3 mm (±2.6, range, 14 20) vs. 9.2 mm (±3.2; range, ), respectively ( p = 0.005). Maximum temporary cavities within the first 15 cm of gelatin were also significantly larger, averaging 121 mm (±5.4; range, ) vs. 38.6mm (± 8.8; range, 30 53) ( p < 0.001). Bullet weights were also significantly larger, totaling 29.7 grams (±1.3; range ) vs grams (±0.01; range ) ( p < 0.01). Using grains, bullet weights were grains (±20 grains; range ) vs grains (±0.15; range ). Using the entire path through the gelatin, as opposed to the first 15 cm as listed in the previous paragraph ( Fig. 5 ), the Krag-Jorgenson bullet averaged 918 mm (range mm) total penetration, with an average maximum temporary gelatin cavity of 128 mm (range mm). This occurred at an average penetration of 485 mm (range mm). In contrast, the musket s bullet traveled an average maximum distance of 685 mm (range mm) through the gelatin. The maximum temporary cavity was achieved at an average of 118 mm (range mm) depth. The maximum temporary cavity averaged 123 mm (range mm). DISCUSSION The wound-profile method is a standard technique used to predict soft tissue wounds and its use has been accepted to predict the wounding potential of a variety of small arms. To the FIGURE 5. Wound profile of the 0.58-caliber musket (top) and caliber rifle (bottom). authors knowledge, this is the first study to document the differences between arms of the Civil War and Spanish-American War to correlate the surgeons findings of both conflicts. In the present study, the Minié ball caused more disruption of ordnance gelatin with both permanent and temporary cavity over the depth of penetration associated with a thigh and torso. The permanent cavity represents the area touched by the projectile as it passes through. For soft tissue with an intact vascular supply, the amount of tissue damage is proportional to the size of the projectile. The temporary cavity is a transient lateral displacement of tissue. Elastic tissue, such as skeletal muscle, may be pushed aside and bruised. Tissue in this area should heal up uneventfully. Inelastic tissue, such as bone or liver, may become fractured by this mechanism. Both the permanent and temporary cavity measurements were significantly larger through the first 30 cm with the Minié balls when compared to the rifle, despite a near doubling of muzzle velocity seen with the rifle. The maximum temporary cavity for the Krag-Jorgenson rifle occurred at almost 50 cm, outside of the average thickness of a torso, with relatively minimal disruption of gelatin occurring in the first 30 cm. The clinical effects of the new full metal jacketed bullet were controversial at the time they were introduced. Griffiths, a prominent surgeon in the U.S. Army Medical Department in the 1890s, tested the new rifle by firing 24 shots into human cadavers at various ranges. He concluded that the newer full metal jacketed bullet was more destructive than the Minié balls and would cause an increased proportion of dead or wounded. Griffiths did not fire comparative shots using Minié balls nor did he comment on the differences between live tissue and cadaveric tissue. Cadaveric tissue is relatively inelastic and stiff when compared to live tissue. Thus, the effects of the temporary cavity may have been exaggerated. 7,8 The U.S. Army Surgeon General s Office sponsored studies to determine just what effect the newer bullets would have compared to the old. Captain Louis A. LaGarde was sent to Frankfort Arsenal, Pennsylvania, to complete this study in He fired shots into human cadavers (52 of a 0.30 caliber, 14.3 gram (220 grain) prototype Krag-Jorgenson bullets and 37 of the standard 0.45 caliber, 32.4 gram (500 grain) bullets of the model 1873 Springfield rifle) and found that the new projectile deformed less, penetrated farther, and appeared less destructive than the older rifle. 10,11 He felt that the newer bullet was more humane in that it would account for fewer amputations than the older rifle. LaGarde then served as a major in the Spanish-American War at a base hospital in Cuba. His observations in treating war wounded confirmed his earlier findings on the effects of the newer bullets. 12,13 The Springfield rifle LaGarde tested was the standard infantry rifle from 1873 until the adoption of the Krag-Jorgenson rifle and was different from the rifle used in our study. The clinical material used in LaGarde s book Gunshot Injuries drew heavily from the experience of the American Civil War (and Minié balls) for comparison to the Spanish-American War (and both the MILITARY MEDICINE, Vol. 174, April

4 Krag-Jorgenson and Spanish 7-mm Mauser). LaGarde did not directly test the Minié ball/rifled musket to the full metal jacketed bullet used in the Krag-Jorgenson, which was the purpose of this article. Surgical techniques had changed in the management of extremity wounds from the Civil War to the Spanish- American War. Rather than amputation, preservation of a limb with an open fracture gradually became the accepted technique during the later stages of the Civil War in certain cases. 18,19 However, treatment of extensive soft tissue wounds, such as those caused by gun shot, were also treated by amputation. 18,19 By the Spanish-American War, antisepsis and the germ theory influenced surgical technique. Gloves, carbolic acid, and improved anesthesia made surgical treatment safer than during the Civil War. Wounds to the soft tissue only were also treated nonoperatively, with only dressing changes as a treatment until the wound had healed. During the Spanish-American War, William Borden, a U.S. Army surgeon, noted that the wounding effects in soft tissue of the full metal jacketed bullet were less when compared to older Minié balls. 1 This allowed for wounds through the soft tissue only to be treated nonoperativley in more cases than had occurred during the Civil War. He also noted that improved surgical techniques of asepsis or antisepsis contributed to the improved results. This decreased mortality is usually attributed to improvements in medical care during this period, but the transition from Minié balls to full metal jacketed bullets may have also played a role. Nicholas Senn, MD, a surgeon on active duty from Chicago University, also treated injured soldiers from the Spanish- American War and found that the wounds to soft tissue were less severe when the newer bullets were used. 14 One limitation of this study is comparing the results of combat casualty statistics from the Civil War to the Spanish- American War. The results cited by Borden from the Civil War are casualties reported to the Army Medical Museum and do not necessarily reflect all patients who were killed outright (killed in action), wounded (wounded in action), and those who died after hospital admission (died of wounds). 18 Casualties from the Spanish-American War were accounted for more accurately than the volunteer reports of the Civil War made to the Army Medical Museum. Less severely wounded soldiers may be more represented in Spanish-American war figures, which may bias the killed-to-wounded ratio cited by Borden. The authors attempted to reproduce the conditions in the nineteenth century as closely as possible. We used original ammunition in an original Krag-Jorgenson rifle. Published 10 muzzle velocities for this weapon were slightly higher (2000 and 1965 fps) than reported in our series (average 1852 fps), probably because of the effects of aging on the bullet powder. Additionally, for the 1861 rifled musket, we used battlefield pick up bullets to minimize differences in modern and Civil War metallurgy. It is unclear just what the average muzzle velocity was for the rifled musket during the Civil War, but it was probably on the order of fps. 10 Various factors are involved with gunshot wounds. The projectile diameter, weight, shape, and composition are all factors. The two projectiles used in this study were different in all bullet variables. The bullets used with the Civil War rifled musket weighed on average twice as much, were less aerodynamically shaped, and were made entirely of soft lead. There are some important findings for those who study gunshot wounds today. Increased velocity is often cited as a factor, and by some authors the most important factor, causing increased wounding. The muzzle velocity of the Krag- Jorgenson rifle was nearly double that of the rifled musket shots (average 1852 fps vs. 944 fps), yet is associated with less destructive wounds in both the present study and historical data. Finally, the type of tissue struck influences the type of injury seen and the patient s outcome. We limited this variable by using a standardized tissue simulant that approximates wounds seen in skeletal muscle. For this reason, our findings only apply to soft tissue wounds. CONCLUSION In the present study, we used a standardized technique that approximates injury of soft tissues. By using ordnance gelatin as a tissue stimulant, we were able to control for variations in tissue type. For extremity wounds, less disruption of soft tissue occurred with the use of full metal jacketed bullets than Minié balls. ACKNOWLEDGMENT The authors would like to thank Paul M. Dougherty, JD for providing comments on the protocol and his technical support during this study. REFERENCES 1. Borden WC : Military Surgery. Bethesda, MD, AMSUS, Edwards WB : Civil War Guns. Secaucus, NJ, Castle, Coates EJ, Thomas DS : An Introduction to Civil War Small Arms. Gettysburg, PA, Thomas Publications, Hutchinson JF : Champions of Charity: War and the Rise of the Red Cross. Boulder, CO, Westview Press, Otis GA, Huntington GC : Medical and Surgical History of the Rebellion, Part II, Vol III, Chapter XII Shot Wounds pp Washington, Government Printing Office, Griffith JD : Some effects of bullets. Proc Assoc Mil Surg 1897 ; 7 : Griffith JD : Experiments with the new United States (Krag-Jorgenson) Army rifle-protection of the soldier. Proc Assoc Mil Surg 1895 ; 5 : Fackler ML, Dougherty PJ : Theodor Kocher and the scientific foundation of wound ballistics. Surg Gynecol Obstet 1991 ; 172 : Girard AC : The latest experiments on the effect of small calibre rifles. Proc Assoc Mil Surg 1894 ; 4 : LaGarde L : Gunshot Injuries, Ed 2, New York, William Wood, LaGarde LA : Report of a Series of Experiments Conducted at Franfort Arsenal. In: Connection with the Ordnance Department of the US Army. Report to the Surgeon General for the Secretary of War. Fiscal Year, pp Washington, Government Printing Office, MILITARY MEDICINE, Vol. 174, April 2009

5 12. LaGarde LA : Remarks upon the gunshot wounds of the reduced caliber rifles in the Santiago Campaign. Proc Assoc Mil Surg ; 8 : LaGarde LA : Remote effects of gunshot wounds by jacketed projectiles. Proc Assoc Mil Surg ; 9 : Senn N : Medico-Surgical Aspects of the Spanish-American War, pp Chicago, American Medical Association Press, Fackler ML, Malinowski JA : The wound profile: a visual method for quantifying gunshot wound components. J Trauma 1985 ; 25 : Fackler ML, Malinowski JA : Ordnance gelatin for ballistic studies. Am J Forensic Med Pathol 1988 ; 9 : Fackler ML : Wound ballistics. A review of common misconceptions. JAMA 1988 ; 259 : Otis GA : Medical and Surgical History of the Rebellion, Part II, Vol II, pp Washington, Government Printing Office, Otis GA, Huntington GC: Medical and Surgical History of the War of the Rebellion, Part II, Vol III: pp Washington, Government Printing Office, RADM Galson and AMSUS Executive Director, Maj Gen George Anderson present the Joel T. Boone Award to CAPT Gary Blair, USPHS (Ret.) for many years of outstanding service to AMSUS Dr. Kussman and Maj Gen Anderson present the Ray E. Brown Award to James R. Floyd VADM Adam Robinson and Maj Gen Anderson present the Outstanding Federal Healthcare Excellence Award to RADM Nancy J. Lescavage MILITARY MEDICINE, Vol. 174, April