I've also considered having Scatter double all range modifiers. This means that they would work out as follows:

Point Blank Range +60

Short Range +20

Long Range -20

Extreme Range -60

Instead of multiple hits from Scatter (which just add too many extra dice rolls, especially with Semi-Automatic or Full Automatic shotguns), give +1 damage per DoS but treat the attack as Primitive.

Taken together, these two changes make shotguns terribly deadly at close quarters against unarmoured or lightly armoured targets. At longer ranges, or against targets with sufficient armour, the shotgun is simply terrible.