Pattern of Firearm Discharge Residue on Cotton Cloth Substrate to Determine the Range of Firing by 7.65mm Caliber of Country Made and Standard Firearm: An Original Research Study

Abstract

The main purpose of the study was to collect a data related to country made and standard firearm from close
range on cotton cloth substrate to determine the range of firing, type of firearm used i.e standard or country
made firearm as limited data are available for such lethality in india. The range of firing is very difficult to
investigate by dispersion pattern of Gun Shot Residue in close range firing by country made pistol. This
study was done to overcome that deficiency.
Method- This study over a period of 3 years was carried out on live cases brought to ballistics division of
CFSL/CBI/New Delhi. Total No. of 180 samples were collected, from three different close range i.e., 4”, 8”
and 12”on cotton cloth substrate. 90 samples were collected by 7.6mm country made pistol and 90 samples
were collected by 7.65mm standard pistol.
Result – Among 180 firing samples during study period, 30 firing has been done from each close range, from
standard as well as country made pistol. The result showed the large variation in dispersion pattern of GSR
from 4” range. At 4” distance, from country made pistol, the inner dispersion area of GSR was calculated
i.e. (7-19 cm2 app.), outer dispersion area of GSR was (30-70 cm2 app.) whereas in case of standard pistol,
the inner dispersion area of GSR was (10-15 cm2
app.), outer dispersion area of GSR was (40-70 cm2 app.) .
Conclusions- It is found that large variation in dispersion pattern of GSR pattern has been observed, when
firing has been done from country made pistol and standard firearm at 4” range. This study must be helpful
in estimation of exact range of firing fired from close range by 7.65mm country made pistol and standard
pistol by analyzing the dispersion pattern area of Gun Shot Residue.