Complete with corny acting and a Garand-type ping to each fired shot, below is the Annual Training video from the US Air Force circa 1967. The video showcases original M16s (not even the A1s were mentioned).
Interestingly, it showcases the original detachable bipods and the carry-handle optic. Further, it shows the original underbarrel grenade launcher, the M-148.
“With the accuracy of a Sniper Rifle”… my how the times have changed.