Boatme98 beat me to the punch. It was an M16A2. Came with a buttstock cleaning kit, a simple nylon sling, six 30 round STANAG magazines and two weeks (x) of free instruction! Followed by a few years of advanced training. Boy, those were the days. I still dream of all those cases of ammo!
(x) In my time, USMC boot at Parris Island was thirteen weeks but the range portion for qualification was a week of 'snapping in' practice followed by a week of four practice days and a day of qualification. AIT involved even more training and eventually I wound up lugging the M60 around, then the SAW and only qualed every year with the M16A2. I still remember my boot issue SN!