Heavier bullets for deeper penetration, for one thing. Instead of Stingers, I'd use Velocitors. If you're getting good accuracy out of Stingers, you're a lucky guy, they've never shown me anything like good accuracy.
I get mixed results out of both stingers and velocitors, in various firearms. Wanna say that it's easier for me to find guns that shoot stingers well, than it is for velocitors.
My little Ruger LCR is very precise with stingers, although I did have one that sorta squibbed on me a few weeks ago. It cleared the barrel but hit the dirt in front of the target. First ever problem for stingers in my experience.
