Basic rifle marksmanship (BRM) involves the execution of fundamental procedures to consistently strike a target in a manner that can be replicated over multiple trials. The Engagement Skills Trainer (EST) is a simulated firing range designed as a cost-saving solution for deliberate practice of BRM fundamentals. In an effort to enhance the EST to support tailored instruction, work has started on integrating adaptive training technologies that enable real-time per-formance diagnosis for triggering objective-based guidance and remediation (Goldberg et. al., 2014). This involves the development of models to support a psychomotor-based training event, both from an expert performance perspec-tive that designates what criteria to score trainee interaction against and a pedagogical perspective that designates how best to instruct when errors in execution are recognized. In conceptualizing the role an expert model plays in a psychomotor-based use case, a question that arises is what impact do environmental factors have on behavior representations? In the instance of the EST, one environmental factor of particular interest is equipment. Specifically, we are interested in the effect variations in equipment have on behavior and performance outcomes, and to determine if the effect is large enough to warrant varying expert models based on equipment setups. In this paper, we present the results of a study comparing behavior and performance data across a set of experts from the U.S. Army Marksmanship Unit. Each expert performed BRM related tasks on the EST across two distinct uniform conditions: (1) wearing just the standard Army Combat Uniform consisting of jacket, trouser, t-shirt and Army Combat Boots; and (2) wearing combat equipment including helmet and body armor. Results will inform expert model implementation and future experimentation for an adaptive marksmanship capability, and may inform more realistic models of soldier representation across training domains.