Comparing Terminal Performance of .357 SIG and 9mm Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

TL;DR

This study compares the terminal performance of .357 SIG and 9mm bullets in ballistic gelatin using high-speed video analysis to evaluate retarding force, cavities, and energy transfer, revealing performance differences among bullet types.

Contribution

It introduces a comparative analysis method for bullet performance in gelatin, highlighting the variability within each cartridge and the impact of bullet design on effectiveness.

Findings

Higher impact energy of .357 SIG bullets yields slightly better performance.

Expanding bullets outperform non-expanding bullets significantly.

Performance variation within each cartridge exceeds differences between cartridges.

Abstract

High-speed video has emerged as an valuable tool for quantifying bullet performance in ballistic gelatin. This paper presents the results of testing four .357 SIG bullets using high-speed video of bullet impacts in ballistic gelatin to determine retarding force curves, permanent cavities, temporary cavities, and energy deposit vs. penetration depth. Since the methods are identical, results are meaningfully compared with four 9mm NATO bullets studied in an earlier project. Though .357 SIG bullets perform slightly better due to higher impact energy, the principal finding is that there is a much bigger difference in performance between the best and worst performing bullets in each cartridge than there is between bullets of similar design in the two cartridges. In each cartridge, higher performing expanding bullets (jacketed hollow points) outperform non-expanding bullets (full metal jacket) by a wide margin, showing a much higher probability of rapid incapacitation according to an Army Research Laboratory model by Neades and Prather (1991).