4e mechanics questions - shotguns

[Ursus Maior]

On modelling slugs:

Many shotguns, but certainly not all, are not rifled guns, but smooth bore. Do we feel this warrants further modifiers for range or is this taken into account by the pistol-like Range of "2" already? I'm feeling the latter, but what are your opinions?

Otherwise, Tegyrius' proposals seem to be the way to go, for me.