A field experiment was organized during a handgun shooting workshop for armed officers (N = 36). In-depth stress analyses involved anticipatory distress, subjective stress, and salivary cortisol reactivity triggered by reality-based handgun shooting practice and, more specifically, by being in an uncontrollable situation with the risk of being shot at. Subsequently, the study examined to what extent exposure to reality-based stress affected working memory performances and self-perceived active learning. As expected, the risk of being shot at caused more anticipatory distress, subjective stress, and increasingly triggered cortisol secretion. Further results showed that, although stress endurance deteriorated working memory performance, participants in the high-realism group simultaneously self-perceivably learned more (i.e., acquired task-relevant skills and competencies). The dual stress effect may result from the professional appreciation of reality-based practice and increased self-efficacy toward hazardous real-life situations. Balancing the intersection between occupational psychology, cognitive psychology, and psychoneuroendocrinology, this study performed stress research in an important and rarely accessible professional setting.