This is the version I heard as a running cadence during my time in the Corps. As NotFabio noted of his version, this cadence is none too popular with the brass or the Staff NCOs with any concern for their career, so you usually only hear it on platoon runs, if then. For the verses the guide would call one line and the formation would repeat it, but for the chorus the guide simply called the first line and the formation answered with the second line.
Grab your bombs and kill some people
Throw some napalm on the square
Do it on a Sunday morning
Kill them on their way to prayer
'Cause napalm, it sticks to kids
Crispy on the outside, gooey on the inside
Aim some missiles at the schoolyard
As the teacher rings the bell
Look at all those kiddies cryin'
As the schoolhouse burns to hell
Throw some candy in the schoolyard
Watch those kiddies gather 'round
Lock and load with my 2401
Mow those little fuckers down
Rape their horses, kill their women
Eat their little babies, too
We're Marines with M-16s
So tell me who the fuck are you?
1)240 refers to the M240G automatic weapon, a 7.62 MM machine gun.