Hmm... let's see...
2350 SS197
25 Tracer (Red)
25 Incendiary
500 SS91
The SS91 is my "go to war" round for the PS90, whether that's zombies, aliens, or rampaging gun-confiscating liberals after a natural disaster. That's enough to fill three 50-round mags (my personal load-out - one in the gun plus two reloads) three times each (plus 50 extra rounds for sighting in and misc. shooting). I'll use the SS197 for my Five-seveN and for squirrel/rabbit/varmint hunting with the PS90. :?