38 AFTE Journal--Volume 44 Number 1--Winter 2012 Introduction The National Fish and Wildlife Forensic Laboratory is charged with assisting law enforcement in prosecuting wildlife crime. Typical victims seen in the Lab include bears, eagles, wolves, etc. In recent years, veterinary pathologists have observed and collected colorful plastic fragments associated with the gunshot wounds. Sometimes the color and shape of the polymer pieces are suffcient to give an indication of the caliber and manufacturer of a plastic-tipped projectile. Such is the case with some of the Nosler Ballistic Tip® bullets, due to a color code assigned to different calibers, however, white tips are used for all the calibers of Nosler Accubond® bullets and olive-drab green is used by Nosler in all calibers of their E Tip® bullets. Hornady uses red-colored tips for all of the bullets sold under the Hornady brand. Hornady also furnishes bullets to other ammunition manufacturers with different colored tips. Hornady V-Max® bullet tips loaded in 17 HMR cartridges are black for CCI and Federal Premium® labeled boxes, gold in Remington boxes, silver in Winchester boxes, and red in Hornady boxes [1, 2, 3]. A previous study considered the physical properties of selected polymer-tipped bullets [1]. Plastic-tipped bullets are designed to have excellent aerodynamics and offer increased terminal velocity and a fatter trajectory. A plastic tipped bullet is in essence a hollow- point bullet that has a pointed plastic tip. Upon impact, the polymer tip assists in expansion of the bullet nose [3, 4]. Rigid polymer tips were originally used to replace exposed lead tips in pointed (spitzer) style bullets. The purpose was to prevent deformation of the bullet tip, which may affect accuracy and trajectory. Damage to the bullet tip could occur Chemical Properties of Selected Plastic-Tipped Bullets By: Melisa C. Thompson, Cady A. Lancaster, Michele G. Banta, Crystal N. Hart, Michael D. Scanlan, and Edgard O. Espinoza U.S. Fish and Wildlife National Forensics Laboratory 1490 East Main Street, Ashland, Oregon 97520-1310 Keywords: plastic-tipped bullets, ballistic-tip ammo, FTIR, XRF, discriminate analysis ABSTRACT Fragments of plastic-tipped bullets are often found in wound tracts of unlawfully killed wildlife. Using color, Fourier transform infrared spectroscopy analysis coupled to the statistical power of discriminate analysis and x-ray fuorescence spectrometry, we were able to characterize the polymers found in common commercially available plastic-tipped bullets. The data is surprising because the high quality control used by the manufacturers provides an opportunity for forensic class character determination. to exposed lead tips during handling, loading into the frearm, or from recoil battering the bullet tips in the magazine. Additionally, the polymer tip helped to expand the nose of the bullet upon impact [2]. The hard plastic-tipped bullets could not be used in rifes with tubular magazines because of the possibility of the hard tip detonating the primer of another cartridge in the magazine during recoil. Conventional bullets for tubular magazine rifes were fat tipped or rounded to prevent detonation of primers due to recoil. The cartridges were classed as short range because of the poor aerodynamic shape causing velocity loss and rainbow trajectories. More recently, Hornady added soft polymer tips in their LEVERevolution® Flex Tip® bullets to cartridges primarily used in tubular magazines [3]. The soft-tipped bullets allow more aerodynamic, pointed bullets to be used in tubular magazines, without the possibility of detonating a primer that the bullet tip is resting on in the magazine. The results have been fatter trajectories and higher terminal velocities. The 2010 Hornady catalog lists the 30-30 Winchester, 308 Marlin Express, 338 Marlin Express, 32 Winchester Special, 357 Remington Magnum, 35 Remington, 44 Remington Magnum, 444 Marlin, 45 Colt, 45-70 Government, and 450 Marlin cartridges loaded with Flex Tip® bullets. Hornady also uses the Flex Tip (FTX)® bullets in their SST® Shotgun Slug and muzzle-loading bullets [5]. The purpose of this study was to determine if it is possible to associate the remnants of evidentiary plastic fragments, suspected of being from plastic-tipped bullets, to a manufacturer through the analysis of the chemical properties of the polymers. The plastic component of these bullets was analyzed using three analytical instruments. A video spectral comparator (VSC) was used to determine color and ultraviolet characteristics, a Fourier transform infrared spectrometer (FTIR) was used to characterize the type of polymer used and a statistical tool (discriminate analysis [DA]) was used to distinguish FTIR spectral differences. Lastly, Date Received: September 12, 2011 Peer Review Completed: December 1, 2011 Page 41 of 49