Mr. Smith,

I'm sure you've heard of angry men putting their entire fist through sheetrock/drywall -a fairly common occurrence. When one compares such a large, blunt object having a relatively modest amount of energy behind it with a very small object driven by a considerably greater amount of energy, it's difficult for me to imagine finding any kind of modern, effective ammunition that wouldn't easily penetrate walls. I'm afraid we have to live with the risk and seek to mitigate it by other means, as suggested by other members here.

I've just realized that what I've written isn't much help -but it might well be something to consider when making decisions like the one with which you're faced.

Regards,
Andy