Quantifying Soldier Shooting Performance of the M4 Carbine with and without a Vertical Grip

Abstract : The Human Research and Engineering Directorate s Dismounted Warrior Branch conducted a live-fire research study where subjects were asked to engage targets at various ranges using an M4 carbine with and without a vertical grip. The objectives of the study were to quantify subjects shooting performance of the M4 carbine with and without a vertical grip and to determine subjects subjective responses on their perceived shooting performance and preferences while shooting the M4 carbine. Of the 18 subjects, 6 were US Army Soldiers and 12 were officers from the local Special Response Team (a local police force at Aberdeen Proving Ground). All 18 subjects fired both weapon conditions in the reflexive posture at 10-, 25-, and 50-m targets and aimed posture at 50-, 100-, and 150-m targets. For the reflexive posture, all subjects conducted 3 training trials with 24 rounds per trial, firing at 24 targets exposed for 3.5 s and later 3 record trials with 24 rounds per trial firing at 24 targets. A similar scenario was conducted in the aimed posture only using 6-s target exposure times. Shooting performance data were collated by the range computer and analyzed for significant differences between weapon configurations. The results of this study showed that for the mean number of targets hit, mean radial error (distance from the point of aim on the E-silhouette target), mean time to shoot, and mean time to hit the target, there were no significant differences in any of the weapon configurations (M4 with and without a vertical grip) in either the reflexive or aimed firing postures, suggesting that perhaps the use of a vertical grip should be left to the discretion of each user.