I tell ya, I use mostly 124/125gr bullet for my 9mm loads but a few weeks ago my son bought a few hundred 115gr Remington FMJ bullet and asked me to load them up for him. I used a charge of 5.0gr W231 under those 115 FMJ bullet and he said they shot great... He did mention they felt like they had slightly less recoil than the factory Remington 115gr UMC ammo but it was close. They were accurate too when shot from a Kel-Tec PF-9.
With a 124gr LRN bullet I load a charge of 4.0gr W231 which is nowhere near the Max of 4.4gr on the Hodgdon site. With a 124gr FMJ bullet I charge 4.6gr which again isn't the Max of 4.8gr on the Hodgdon site. Both loads make great practice range ammo.
With a 124gr JHP bullet my favorite load is 5.7gr Longshot, it's a stout load...