17 (just a few months shy of my 18th BD). It was either an M-16 or the S&W Model 15 during summer training at Jack's Valley, don't remember which one I shot first.
Two years later I was an Instructor/Range Safety Officer on the Model 15 during the same trianing for the Class of '69.
Two years later I was an Instructor/Range Safety Officer on the Model 15 during the same trianing for the Class of '69.