Horizontal Aiming-Point Variability Differs Between Reduced-Distance and Original-Distance Shooting Conditions in Olympic Rifle Shooters

Reduced-distance dry-firing is widely used in rifle shooting when access to full-distance ranges is limited. However, even when target size and height are adjusted, reduced-distance practice alters the geometric relation between translational and rotational control demands and may therefore affect the comparability of aiming-related performance indicators. The present study examined whether horizontal aiming-point variability differs between reduced-distance and original-distance shooting conditions in Olympic rifle shooters. Routine training-monitoring data from 13 national -squad athletes were retrospectively analysed. For the first research question (RQ1), 5 athletes provided both reduced-distance dry-fire observations during the COVID-19 lockdown and original-distance live-fire observations before or after lockdown. For the second, exploratory research question (RQ2), 8 athletes provided original-distance live-fire observations both before and after lockdown; 2 of these athletes had performed reduced-distance dry-firing during lockdown (exposure group), whereas 6 had not (control group). Aiming-point kinematics were recorded with the SCATT MX-02 system. Horizontal aiming-point variability was quantified within an individualized hold phase identified by an adaptive phase-segmentation algorithm. For RQ1, the final analytic sample comprised 2484 shots. Horizontal aiming-point variability was lower under original-distance conditions (M = 6.91 mm, SD = 2.40) than under reduced-distance conditions (M = 10.00 mm, SD = 4.10). In the final linear mixed effects model, reduced-distance conditions were associated with higher horizontal aiming-point variability than original-distance conditions, Estimate = 1.60 mm, 95% CI [1.02, 2.18], t(2482) = 5.38, p < .001. For RQ2, the final analytic sample comprised 1889 original-distance live-fire shots. The group × phase interaction was significant, Estimate = -1.07 mm, 95% CI [-1.90, -0.24], t(1885) = -2.54, p = .011, indicating that the pre- to post-lockdown change differed between groups. However, this exploratory finding should be interpreted cautiously because the exposure group comprised only two athletes. Reduced-distance dry-firing was associated with acutely higher horizontal aiming-point variability than original-distance live-firing. The present findings may be interpreted in terms of at least three non-exclusive explanations: geometrical scaling effects, altered motor-control compensation under reduced-distance conditions, and distance-dependent projection issues in the measurement system. In addition, the exploratory pre-post pattern suggests that longer-term adaptation cannot be excluded. Controlled research is needed to determine the relative contribution of these explanations to reduced-distance effects on stability of hold.