SR4 would have to be my current primary:
Ruger Super Warhawk
+Internal Smartgun system
+Ammo skip system
+Improved Range Finder (as soon as I have the cash to fit it)
+Increased Cylinder
+Fire Selection SA
+Personalised Grip
Loaded with 4 SnS, 2 APDS, 2 Ex-Ex
3 speed loaders tricked out with 8 SnS, 8 APDS, 8 Ex-Ex (make sure you know which is which).