Phew, and I had some stuff by an avid hand gun hunter who says there is no such thing.
Pistols are not under powered, they just are not powerful. Its like saying my car is under powered compared to a Ferrari. While granted I can't afford a Ferrari, I would also not want one as it does not work for me.
Ergo the wagon does that job better than a Ferrari does for what I need and do.
A pistol has a certain level of power and its less than a rifle because its smaller and handier. I give up speed and cornering in the wagon for capacity. You give up a large caliber heavy hitting gun for a pistol because a pistol works better to carry, keep in a drawer conceal etc.
And at what point does your heavy caliber gun just blow through and you still get nothing? Bid difference between a deer sideways with a nice spitzer lead tip that you blow the lungs and or heart out and a human coming at you with mayhem on his mind.
You just accept that nothing form 9mm to 44 magnum is going to be a one shot stop ever and keep shooting until the threat is gone.
The serious experts seem to think the 124s are preferred in 9mm so that's what I go with. Others disagree and feel the 147s are better and I think you can go that way and very likely be fine.
I don't see anyone shooting through gels with ribs, shoulder blades with gelatin behind it or an arm or leg bones and geletin in various ways. It proves nothing other than being able to measure a result of penetration between bullets and designs. It does not mean you will get your 18 form the 124 or 11 from the 147 if you actually shoot someone.
Real world says its shot placement not bullet size nor caliber.