Originally Posted by murphydog

Good to think about these kinds of issues beforehand.

Someone here will be able to recommend a .223/5.56 mm round that is more likely to fragment on a hard object like brick or a wood beam. Figuring out the most likely angles and directions that shots will be fired, and from there where a projectile may travel, is a good idea.

I recall that there were studies looking at the overpenetration potential of 9 mm vs. .223 longarms that showed there was less with the .223. I suspect this is why I think there are relatively few agencies using the 9 mm submachine gun currently.

A good idea to be very familiar with all your guns and train regularly. Stay safe!