No pun intended rimfire, but that's kind of a loaded question. lol
Mine eats almost anything I feed it. But they can be somewhat finicky about the ammo they'll eat.
However sometimes ammo or the gun is blamed for problematic cycling of these small light wieght and powerful
guns. When in reality many times it's the grip. Like HP's the KT's are sesitive to limp wristing, or what I like to cal "strong elbowing". You need a good push pull grip and both elbows bent to keep the energy of the slide moving horizontally rather than vertically. ;-)
That being that, I mainly use WWB and Blazer 115gr. for my range ammo. And SXZ 124 or 115gr. JHP for my defense loads. The only thing I've found that my PF9 doesn't like much is 147gr. ammo.
Oh ya, and a laser for these guys can go a long way towards helping you learn to control that long DAO trigger. ;-)
Armalaser RSS on mine.
Both of my reloads ran great but accuracy was not as good as I would like, course these loads were tailored to hit POA from my S&W 9VE Sigma and HP C9, both having a bit longer barrel than the PF-9.
The 147gr WWB's.... lets just say they produce as much recoil in the little PF-9 as some of my .44 Special loads do in my Taurus 441 4" revolver. Accuracy was so-so but still in the black on a B27 at 12 yards.
The Hornady 115gr loads turned in better accuracy than any of the heavier bullets did, recoil was very manageable for rapid fire.
Based on the two range sessions I have had so far I may lean towards the lighter 115gr bullet in this pistol because it seems to put em where they belong a more consistantly than it did with the heavier bullets. This is the beauty of reloading.... matching up bullet/powder/charge to what a particular gun likes!! Fun Fun Fun.
Sounds like you've got a good handle on figuring out what your gun will like. ;-)
Just remember that running any +P ammo through it is a no no with these light weight guns.
So keep those loads reasonable. ;-)