Using human-centered design to improve the assault rifle

The objective of the present study was to interview infantry soldiers to determine their preferences with respect to rifle design and to examine the effect of buttstocks on shooting performance. Factor analysis showed that seven main factors should be considered in rifle redesign including tactics necessary, interface design, saving weight, bullpup configuration, sight design, other devices, and bayonet lug. For the shooting experiment, a total of four shooting trials were performed with the T-91 rifle, with buttstock lengths of 26 mm, 34 mm, self-adjusting stock, and bullpup stock. The analysis revealed that buttstock length had a significant effect on shooting performance. The redesigned rifle weight and total length should be reduced to 3.2 kg and 750 mm, respectively. The rifle buttstock should be a non-adjustable bullpup style. The buttstock shape should be curved and the hand-guard type should be more deeply and density seams, while the trigger handle shape should be slanted.