Just thinkin' here.
My 9mm will punch through some sheetrock, the back of a sofa and still have a little sting left to it. My clip holds 20 rounds (pre-limited clip days)of hollow points, so I can be very generous to my 'guests'. In the short range 'home turf' area; it's plenty lethal.
However, I do not think that my 9mm will likely exit my brick exterior, go into my neighbors brick exterior and ruin his day. If I had a 45; I'd have to be more stingy with the ammo. I sure hate to feel stingy when I have a guest to 'entertain'.
That's why I went 9mm. Sometimes limited penetration is a good thing. Now, in a police or military setting; I think we would both prefer the biggest, meanest and power packed punch we could get. But not in the middle of Surburbia. At least IMHO.
I've got 15 .45 rounds in my Para-Ordnance and I imagine it will penetrate less than your 9 due to lower velocity. It just makes a hell of a lot bigger hole.
If 15 .45 hollow points won't deal with the matter, I give up.
If you just gotta have a Beretta, consider one chambered for .357 SIG.
So9
"My clip holds 20 rounds (pre-limited clip days)of hollow points, so I can be very generous to my 'guests'."
I have a six shot revolver and that will entertain any guest enough to make them wish they hadn't dropped by. LOL