This manual provides guidance for planning and executing training on the 5.56-mm M16-series rifle (M16A1/A2/A3/A4) and M4 carbine. It is a guide for commanders, leaders, and instructors to develop training programs, plans, and lessons that meet the objectives or intent of the United States Army rifle marksmanship program and FM 25-100 (Training the Force). This manual is organized to lead the trainer through the material needed to conduct training during initial entry training (IET) and unit sustainment training. Preliminary subjects include discussion on the weapons' capabilities, mechanical training, and the fundamentals and principles of rifle marksmanship.