Ballistics

Ballistics Gun violence is a serious problem in today’s society and understanding how guns and their ammunition work is important to understand to be able to solve crimes. One of the pillars of forensic investigation is the science of ballistics. Wikipedia defines ballistics as the science of mechanics that deals with the flight, behavior and effects of projectiles (Wikipedia). Understanding how the bullet with react when striking various surfaces is crucial to any investigator. With 68% of all U.S. homicides that were committed in 2011 with firearms, it is evident ballistics is an important way to solve these crimes (Crime in the US). To understand ballistics you need to understand rifling, identifying features of fired ammunition, and the examination of the ammunition and firearms. Helical grooves known as rifling are cut into the bore of a barrel of a firearm during production to increase the accuracy of that firearm. When the gun is fired, these grooves cause the bullet to spin as it travels the length of the barrel and thus stabilize the bullet during flight. At the same time, the expansion of the fired cartridge and the high pressures propelling the bullet through the bore of the barrel press and scrape the bullet against the rifling as it heads toward the muzzle. The fired bullet, as a result, will bear the negative impressions of the grooves in a rifled barrel; these marks are described by firearms examiners as land and groove impressions, or lands and grooves. In addition to the rifling marks produced on a bullet by its passage through a gun barrel, a number of other impressions found on cartridge cases and resulting from machining processes are crucial to firearms identification. Firing pin impressions, breechface marks, extractor marks, ejector marks, and chamber marks, when present and of sufficient quality, are all features used by firearms examiners in their analyses. During the discharge of a firearm, the firing pin strikes the primer of a

References: ”Ballistics.” Wikipedia. Wikipedia, n.d. Web. 27 Jul 2013 “Crime in the United States 2011.” FBI. FBI, n.d. Wed. 27 Jul. 2013