I'm away from my books at the moment, but I thought of the Sakura Fubuki. Does that fire from each barrel in one burst or does it fire one barrel? Because you can load one barrel with one of the types of ammo... But reloading would be a pain, so extended "clip" and additional "clip" would be necessary.
EDIT:
Well, SR4A doesn't say if the Fubuki fires from each chamber or from one. For our purposes, we can use it as a base:
Sakura Lawgiver
- High-Power Chambering (for one of the chambers)
- Extended Clip (13 rounds each)
- Voice Activation / Response
- Advanced Safety, Explosive Self Destruct
- Smartgun (External)
In the movie, Dredd used Stun, High Ex, Normal, and Armour Piercing I think. So, that's SnS, HP, Ex-Ex, and APDS.