Effects of Shooting Angles and Ricochet Angles on Bullet Weight Upon Impact on Three Types of Woods (Balau, Resak, and Seraya)

Abstract

This study aims to determine if the number of shots fired, bullet striation marks, and shooting and ricochet angles could influence bullet weight on three types of woods: Balau, Resak, and Seraya. The weapon and ammunition used in this study were CZ 75 SP-01 Shadow semi-automatic pistol with 9 mm full metal jacketed bullets (7.45 g). A total of 432 shots were fired, and only 114 bullets produced a ricochet effect. The result of objective one showed no significant relationship between the number of shots and the number of bullet striations for all three kinds of wood. Correlation-Regression analysis for the second objective showed a significant relationship between shooting angle and bullet weight when shooting on Balau (p < 0.01, R² = 0.065) and Seraya (p < 0.01, R² = 0.199) but not on Resak. The shooting angle influenced the bullet weight by 6.5 % to 20 % when shooting on Balau and Seraya. Both kinds of wood are closely related and share fibre composition and modulus of elasticity (MOE) characteristics. The result of the third objective showed a relationship between ricochet angle and bullet weight during the shooting on Resak (p < 0.01, R² = 0.142) but not on Balau and Seraya. The ricochet angle on Resak influenced the bullet weight by 14.2 + 9.8 %. It is probably due to Resak having the highest MOE among the three types of woods. This study concludes that bullet weight loss is due to the ricochet effect and the composition of the bullet’s target.