I don't know if this has been posted yet, but I caught part of a Mythbusters episode last night where they were testing hitman myths. In particular, they were testing if a hitman could fire through a wall and kill his adversary on the other side. They were using either a Beretta M9 or 92 (I couldn't tell which), and what they called "standard" 9mm hollowpoint ammunition clocked at 1200 fps. They fired through lathe and plaster, two sheets of 1/2 inch drywall filled with insulation, drywall/2x4, drywall/metal stud, drywall and copper pipe, and drywall with a double sided steel junction box. Neither the lathe and plaster or drywall slowed the bullet past 1050 fps or deformed the bullet much. The drywall and both types of studs failed to slow the bullet much past 900 fps. The drywall copper pipe deflected and deformed the bullet, but it still retained over 700 fps velocity. Only the drywall and steel junction box stopped the bullet from passing through the wall completely.