After trying HS-6, WSF, WST, and 231, I've settled on WST. The following load is accurate, soft, cleaner than the rest, provides positive ejection on a G34 with a 14lb Wolff recoil spring, and provides positive ejection on a G19 with a stock RSA.
147 Bayou Bullet
3.3 WST
1.150 OAL
~915 FPS at 50 Degrees F
G34 KKM Barrel
ES 10