Either Corbon PowrBall 135 gr .40 S&W or McNett's Double Tap 135 gr. Nosler JHP? I have one in my flush mag, and the other in my extended. I really got them for my Full Size .40, and I know I'm losing velocity and muzzle energy in the shorter barrel, but I trust both rounds and they cycle well in both guns. Most important, they go where I send them, every time.
Maybe somebody can talk to me about good reasons to switch to a round designed for a short barrel. I'm open to change, I just kept on without changing when I got the Shield.