RARDEN ammo comes in clips of 3, so if the number is not divisible by that, it is suspect
!
The weapon holds 6 rounds in the breech, fed from 2 strippers. It's really used as a rather large Self Loading Rifle on semi-auto, with a capability to fire a burst of 6 maximum at a very low cyclic rate (180 springs to mind).
It's a very accurate weapon (at least back in the 70s when introduced, I no longer have the Janes Infantry Weapons 1976 I used to), but not really an "auto-cannon" in the full sense. Full bursts of 6 were typically reserved for e.g. shooting at helos with.
Andy