[runjake]

This isn't to confirm or refute your information, but rather some points:

- Houses that were penetrated by stray .223 rounds from football fields (aka multiple hundreds of meters) away probably weren't rounds shot through drywall. Maybe from outdoors, or through a window, who knows.

- .223 rounds that encounter no obstacles in flight have a flat trajectory of about 200 meters (2 football fields). .223 rounds that penetrate any substance of sufficient density have their flight path altered.

- In my limited experience with buckshot (none with residential materials), it's probably going to have a relatively flat trajectory, even through drywall. Something to especially consider if you have other people in your home.