Hate to break it to you, but a hollow point can penetrate walls and continue on for some way as well. A large minority of the time, a JHP will get some crud in the hollow point as it first hits something and then acts like a FMJ round.
And a hollow point is different from a frangible round. Frangible rounds aren’t worth squat for self defense.
If the HP round expands as its supposed to there shouldn't be a 'through and through' like with Ball Ammo. Naturally this gets into the ballistics of the caliber used and a round's energy. Like a .308 or 7.62x39 compared to a 9mm +P.
And I know a HP is different than a Frangible. As to them not being 'worth squat' for self defense, I've seen that published lately. Like when the 'target' (bad guy) is wearing heavy or multi layers of clothes. But in summer that isn't likely. (That's also why I have more than one magazine for my pistols)
All that being said, I've also seen it said that 'only' a 12ga Shotgun is good for Self Defense. And a .45 ACP is the 'only' round good for self defense. Which really means its all a matter of personal opinion and choice .
About a week ago on a thread a Firearm Expert was quoted. He said,
'A .22 to the eye is better than amiss with a .44.And that was really the point of my post and the gangs killing innocent people. Gang-bangers are terrible shots. They spray bullets everywhere hoping to hit the person they want to kill. And with FMJ rounds, collateral damage is more likely. (all things being equal)