well, that's just for trying to hit multiple targets, the whole fingercone thing. for shooting minifigs multiple times, it's a whole 'nother story. luckily for you, it's a system that's even EASIER to remember than the spread-fire one.
to shoot a minifig multiple times, lower the weapon's UR by one, and make a skill roll. for every number ABOVE the UR that you rolled, add an extra point of damage to the shot (as in, you've got a short range weapon with UR 3 and 1d6 damage. a minifig wanting autofire would lower the UR to 2 and then roll skill to see how good he is at it. let's say he rolls a 5: 5 - 2 is 3, so he does 1d6 + 3 damage). also, any minifig within 1" of the target takes normal weapon damage, and on a critical fail the weapon is out of ammo and must be reloaded.
That, basically, is the summation of the billingsly rule version for automatic fire. Blitzen has a very similar method as Billingsly, but it combines the two firing modes so that instead of having two ways to shoot, there's a much more customizable, single way to shoot. i'm still not sure who's rules i prefer.