Metro, that 1/16 steel sheet link doesnt work, and I can tell you from experience that even a .22 will go through 16 ga sheet.

7.62x39 fmj's will go through 1/4" ms plate!

but you also have to remember, at least up here, we live in stick frame houses, so even fortifying a room will be of limited use if the bad guys decide to burn the place.