I use Winchester White box 100 count, 115gr FMJ (Walmart),
Geco 124gr FMJ,
Carrolls remanuf. 124gr RNL (for indoor range); real dirty.
The Geco is higher pressure stuff, I believe >+P, loaded to CIP specs of max 39,200 psi (SAAMI limit for +P, 38500).
Trying to verify the Geco pressure with Dynamit Nobel.
I use Winchester white box 165g FMJ from Walmart for practice. I've put well over 600 rounds of this through my P99 .40 with no malfunctions (gun or ammo-related) at all. I use Federal Hydra Shok 165g for SD.
I have had a good experience with Fiocchi's .40 S&W, 170 grain, FMJTC. (Over 1000 rounds, no malfunctions.) -I picked mine up from Ammoman.com since I buy in bulk (500 round lots) and the shipping is free.