I´ve already considered the .45 ACP, but I would like to stick with the 9mm, because I train a lot, so ammo costs are a huge factor.
I´ve read a several articles about wound ballistic, and I think I could say the basic conclusion is, that shot placement, reliability and sufficient penetration are far more important than expansion, when you have to defend yourself with a handgun.
So I think I will go for the Fiocchi 100grs JSP Flat. I know, that this ammo works perfectly in my glock, and the ammo costs are affordable, so it´s possible to practice with it a lot.
By the way: Is it true that the ammo costs are currently exploding in the US? Is this because of the person called "double barrel" Biden?