I find it hard to believe I would have made such an error. Are you sure I wasn't speaking of the M16A2's predecessor? If I did say "7.62" in reference to an "M16A2", I was in error. I doubt it, however, since rifle specifications are a part of "daily prac" in Boot Camp. The whole "...lightweight, air-cooled, gas-operated, magazine-fed, shoulder-fired weapon capable of 3-round bursts or semiautomatic fire..." type phrases of knowledge were daily requirements. Distances of area and point targets, maximum effective range...all statistics which were eaten, slept on, and shat.
For me to make an error in this regard, would have taken a severe account of sleep deprevation (which is plausible considering during my time in the Corps I had conditioned myself for 1-2 hours of sleep per night) or simply, your statement of my proposed statement is in error, itself.