Go find yourself some Nato/Win 124gr FMJ's. Academy has them on sale here right now. They are a near +P round. But will give you a idea of how 124gr slug will work in your pistol.
Only reload 124gr. FMJ for my Sigma and PF-9 for range ammo. Currenty Berry's Bullets. Being plated I keep the powder charge on the low side as if I was loading for lead. Should be moving on the Precession Delta Bullets soon for my range work. I also load up XTP bullets in 124gr and 147gr. I load them a tad hot and they are a blast to shoot!
I dislike 115gr ammo. And only buy it for range rags when I find it dirt cheap and more concerned about collecting the brass than shooting the rounds.
Just look around,,, there is 124gr. and 147gr retail ammo out there in FMJ and JHP. WWB can be found around here in 147gr pretty easy. Try some of that stuff. My Sigma is loaded up with 147gr stuff right now for HD use.
Good luck in your hunt.
It's worth the effort. Give simple reloading a look. A whole world opens up to the shooter.....