THE PECULIARITIES IN THE FORMATION OF GUNSHOT WOUNDS CHANNELS CAUSED BY 7.62 MM EXPANSIVE «HPBT» AND «SP» TYPE BULLETS

The aim of the study – to study the peculiarities of wound channel formation, causedby 7.62 mm «HPBT» and «SP» bullets, by means of experimental methods of forensicballistics with the use of human biological tissue simulators.Materials and methods. Experimental investigations were carried out under conditionsof the ballistic route of the National Scientific Center «Hon. Prof. M. S. Bokarius ForensicScience Institute». To determine the velocities of the fired bullets, the optoelectronicmeasuring complexes IBX-731.4 were used. Ballistic plasticine «Beschussmasse,6287156» was used as a simulator of human body tissues. The experimental shooting wascarried out with a TS.M308 model .308 «Winchester» sniper rifle. For the experimentalshooting 7.62 × 51 mm (.308 «Winchester») cartridges were used, which were filled with«SP» and «HPBT» bullets.Results. In the course of experimental shooting, the peculiarities of the formation ofdamage channels caused by 7.62 mm «SP» and «HPBT» bullets were determined. Basedon the results of experimental studies, it has been found that the bullets of these types ofthe same caliber and practically the same mass are able to cause different amounts ofbodily injury, which is primarily due to the peculiarities of the design of the bullets. SPtype bullets with a bare core cause more severe bodily injuries, they are less subject tofragmentation and in most cases retain a relatively heavy bottom part. As a consequence,such bullets are able to cause longer wound channels than other types of expansivebullets. HPBT-type bullets can also cause sufficiently large amounts of bodily injury,but because of their design, they are more prone to fragmentation when hitting thehuman body. In the course of the research it has been established that there are severalperipheral (secondary) channels in the area of the main wound channel. They are formeddue to destruction of the bullet and movement of its separate fragments away from themain direction, which leads to complication of diagnostics and further treatment of suchgunshot wounds.Conclusions. The use of 7.62 × 51 mm (.308 «Winchester») expansive «SP» and «HPBT»type bullets in the course of combat operations for firing modern sniper systems resultsto severe bodily injuries. Wounds caused by such bullets are characterized by significantin volume zones of direct traumatic necrosis (contusion), which significantly extend deepinto the tissues and structures of the human body and form even larger in size zonesof conditional necrosis (contusion) and morpho- functional changes. The formationnature of both the main wound channel and the peripheral wound channels, caused byfragments of bullet structural elements, depends on the velocity, design features andposition (projection) of the bullet at the moment of impact. Changes in biological tissuesin the area of wounds caused by these types of expansive bullets have rather complexarchitectonics, which significantly complicates the issue of clear delimitation of gunshotwound zones and adequate surgical intervention. The used investigation methods of thestriking properties of expansive bullets are suitable for predicting the severity and volumeof the caused injuries, as well as for determining the individual characteristic complex ofgunshot wounds signs caused by such bullets.