Historical De\Felopmerit of Shotgun Rifled Slugs
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If you have issues viewing or accessing this file contact us at NCJRS.gov. r~ril1991- ip u.s. Department of Justice ,f Volume 18, No.2 Federal Bureau of Investigation r . Crime Laboratory, 1)igest I ~ l h f; __~ __~ __~ ______~ ____________~~ ___ i . · I 11 In This Issue , Historical De\felopmerit of Shotgun Rifled Slugs , ' <' '.,1 ~ "and the P'o/ice lJ,se of Shotguns , Gukjelines for a Quality Assurance Program for DNA Analysis lfI', 1 i ~ Contents Message from the Assistant Director in Charge 31 of the FBI Laboratory Editor's Column 33 Feature Article: Historical Development of Shotgun 36 /3:J.;k)..q Rifled Slugs and the Police Use of Shotguns Edward W. Killar 1 discusses the historical development of shotgun rifled slugs in the United States and the use of shotguns by American law enforcement officers. /3~Q.Bo Feature Article: Guidelines for a Quality Assurance 44 Program for CNA Analysis The Technical Working Group on DNA Analysis Methods and the California Association of Criminalists Ad Hoc Committee on DNA Quality Assurance present revised and expanded guidelines for establishing a quality assurance program in crime laboratories conducting DNA analysis. Meeting Announcements 76 Instructions for Submitting Articles 78 132229- 132230 u.s. Department of Justice National Institute of Justice This document has been reproduced exactly as received from the person or organization originating it. Points of view or opinions stat:d in this document are those of the authors and do. not nec:ssanly represent the 1)fficial position or policies of the National Institute of Justice. Permission to reproduce this 1111 _ ,pmaterial has been granted by Public Domain/FBI u.s. Department of Justice to the National Criminal Justice Reference Service (NCJRS). Further reproduction outside of the NCJRS system requires permis sion of the~ owner. CRIME LABORATORY DIGEST Vol. 18, No.2, April 1991 ISSN NO. 0743-1872 IFearure Micle I 13:Jdd...0; Historical Development of Shotgun Rifled Slugs and the Police Use of Shotguns Edward W. Killam Alliance Services Boulder, Colorado 80303 Until about 1850, alliong arms and handguns bullet invented by French Captain M. Minie. were smooth bore weapons. The armies of the The undersized Minie bullets could be loaded major powers were armed with smooth bore easily into a rifle muzzle without patching. muskets, adequate for hitting man-sized targets Upon firing, the hollow, conical base spread to up to a 100 yards away. Prior to 1855, the grip the rifling of the barrel. The great mass of United States military musket was a smooth bullet was forward as it traveled through the air bore, firing a .69 caliber (approximately 16- with its skirt-like base behind. This badminton gauge) spherical lead ball (Petty and Hauser birdie shape made the bullet stable in flight. 1968). Most military long arms were full-length The same principle was later applied to shotgun wood stocked muskets, whereas civilian "fowling slugs designed by Wilhelm Brenneke and Karl pieces" were half -stocked arms. Shortly after M. Foster. Brenneke's weight-forward design their introduction, all Western powers adopted depended upon lightweight wads attached to the new rifled arms. rear of the slug, whereas Foster's slug more Shotguns are a continuation of the fowling closely copied the Minie design in that its base piece tradition. They are still smooth bore is hollow and lightweight (Figure 1). weapons. Chokes first appeared on shotgun barrels around 1870. Previously, they were all completely open tubes so that either ball or shot Brenneke's Slugs could be fired. By 1880, most shotguns had choked barrels. This made it difficult to. accu The Germans were pioneers in the develop rately fire lead balls because, for the ball to fit ment of shotgun projectiles other than lead balls. tightly in the barrel, it would not pass through Patented shotgun projectiles appeared as early the choke. Until 1900, many shotgun barrels as 1890, the most famous being that of Wilhelm with chokes were stamped "NOT FOR BALL." Brenneke. The Brenneke slug was first pro To compensate for the new choked shotgun duced in Leipzig, Germany and patented in 1898 barrels, lead balls were made smaller. Previ (Sterett 1966). It has only been slightly modified ously, a 12-gauge ball had approximately a since then and remains in regular production . 729-inch diameter and weighed about 1.33 oz. It is manufactured in several countries such as After choking was introduced, balls were typ Germany, Belgium, Spain, Italy and France. ically made with a .645- to .660-inch diameter The Brenneke slug has never been widely pop and weighed less than 1 oz (Sears 1981). When ular in the United States, perhaps because it is lead balls were made .040 inches smaller, the more expensive and less accessible than the accuracy suffered because of the loose barrel fit. American made Foster slugs. Even so, the balls survived in shotgun shell loads The lead portion of the slug is made in full in the United States until 1941, and they are still bore diameter so that it does not need to be available in Great Britain. These 12-gauge lead initially expanded at ignition. The slug has 12 balls, commonly called "pumpkin balls," are so slightly angled swaged ribs. The nose has a small that they can even roll down the barrel of small conical point and a square shoulder, unlike a 16-gauge shotgun. Although inaccurate, they the rounded nose of the Foster type slug. The are very safe and not likely to become lodged in Brenneke slug has a slight hollow in the middle even the tightest choke. Some shooters hand to allow for swaging as the slug passes through loaded their own shotgun shells, putting patches the choke. A wad column is attached directly to around the balls to make them fit more tightly. the base of the slug by a screw. The wadding Meanwhile, to take advantage of the new serves not only as a gas seal with the barrel~ but rifles, round balls were gradually being replaced as a light tail portion to increase stability of the by pointed projectiles such as the hollow-based slug in flight (Figure 2). 36 CRIME LABORATORY DIGEST Vol. 18, No.2, April 1991 Figure 1. The Minie bullet (left) pioneered the Figure 2. Both the Remington slug (left) and weight-forward, hollow base design closely the Brenneke slut!, (right) use wadding to im copied by the Foster-type rifled slug (right). prove the gas seal between the smooth shotgun barrel and the projectile. Foster Slugs of the slug was further reduced for safety so it would pass through even the tightest choke. The most common rifle slug in the United The basic Foster slug, however, remains a States is based on the design of Karl M. Foster hollow lead cup, heavier at the point. It has 14 of Great Barrington, Massachusetts. He devel small angled ribs swaged into the side of the oped the slug in 1931 for his personal hunting slug. The rifling tends to be obliterated by the use. Foster originally ca'lt the slugs to shape in passage of the slug through the barrel, especially a 20-gauge barrel and then cut the grooves into through a full choke. Some spin does result the sides with a file. He subsequently obtained from the ribs, however, and tests show a very a custom-made mold from the Lyman Company slow spin of approximately one turn in 24 feet (Middlefield, CT) and rifled the castings in a of travel to one turn in 129 feet of travel, handmade die. He soon made the slugs available depending upon the choke used. In 1980, to his neighbors. Remington and other slug manufacturers in In 1932, some of the Foster slugs were sub creased the weight of 12-gauge rifle slugs to a mitted to the Remington Arms Company. Ex full 1 oz. periments showed that they were more accurate Neither Brenneke nor Foster slugs depend than balls, but Remington was apparently not upon the rifling ribs or projectile spin for sta inclined to develop them further. In 1933, bility. The slugs are stable because they travel sample slugs were sent to the Winchester Arms through the air like a sand-filled sock with the Company, where they underwent extensive heavier toe forward (O'Connor 1965), unlike testing. Winchester accepted the new design, symmetrical lead balls (Figure 3). The trailing and factory loaded shells were first placed on light end acts as a stabilizer. The slight rotation the retail market in September 1936. The imparted by the ribs reduces the effect of man Remington Company soon recognized its error ufacturing irregularities. In tests performed and added them to its product line in 1937. by Winchester-Western, the slu.g rotation was Foster type rifle slugs are now manufactured by confirmed, resulting in consistently smaller Remington, Winchester-W~stern and Federal groups for rifled slugs than unrifled slugs (Anoka, MN) cartridge companies. Lyman (Sterett 1966). continues to make casting molds and a swaging kit for hand loaders. The first factory loaded slugs differed from 12-Gauge Slug Ballistics those of Foster originals in that the weight was reduced to approximately .875 oz. Also, Foster Some manufacturing specifications for three had originally placed wax in the hollow base of rifled slug loads are summarized in Table 1. his slugs so that accuracy would not be dimin The table shows that Foster style slugs are made ished by cardboard wadding sticking to the base. well below the actual 12-gauge bore diameter. In lieu of wax, Winchester and Remington used Brenneke slugs are made quite close to actual a hard cardboard wad at the base.