Measures of rifle marksmanship skill and performance were developed using a prototype instrumented laser-based training system. Measures of performance were derived from laser strikes on a video-projected target. Measures of rifle marksmanship skill--breath control, trigger control, and muzzle wobble--were developed from shooters' breathing and trigger squeeze patterns. Existing marksmanship instructional materials and expert shooters' breath and trigger control profiles guided the development of the skill measures. A shooter's breath control was described as where and how long into the respiratory cycle the trigger broke. A shooter's trigger control was described as the duration of the trigger squeeze. A shooter's muzzle was described as the total acceleration during the two seconds prior to the shot. The use of sensor-based measures provides insight into exactly how a shooter is executing two of the three skills considered to be the fundamentals of rifle marksmanship. (Contains 9 figures, 2 tables and 1 footnote.) [This report was supported by a grant from the Advanced Brain Monitoring, Inc., PR/Award Number 20064169.]