FSC239Y5 Lecture Notes - Comparison Microscope, Trace Evidence, Nitrocellulose
Document Summary
2- smooth bored (barrel) weapons- shotguns and antique weapons. Rifling is a series of parallel spiral grooves cut the length of the bore of the barrel. The metal left between the grooves are the lands. The fun barrel is produced from a solid bar of steel that has been hollowed out by drilling. Rifling imparts a rotational spin on the bullet. The caliber is the diameter of the bore (land to land) 6 (diameter) x 39 (length of the cartilage) Shotgun has smooth barrel, fire small lead balls or pellets. The diameter of the shotgun barrel is expressed by the term gauge; the higher the gauge number, the smaller the barrel"s diameter. Caliber of the shotgun is expressed by its gauge. These striations form the individual characteristics of the barrel. Repeated use of the weapons, imperfections of the metal. The inner surface of the barrel of a gun leaves its markings on a bullet.