If you want the artillery randomly exploding in an area with a radius of 100 meters, do something like this:
_bang = "maverick" camcreate (random 100 - random 100), (random 100 - random 100), 400]
Or if you want the area with a diameter of 100, do something like this:
_bang = "maverick" camcreate (random 50 - random 50), (random 50 - random 50), 400]
Naturally the shells will be more concentrated in the middle, but they should be quite randomnized.
-Pilot