I caught a couple minutes of a shooting show last night where the host was shooting various ammo through multiple wallboard panels to simulate what might happen in a HD situation. I didn't catch all of the specifics on bullet weights and types (need to go back to the DVR and watch it all), but unless I heard him wrong, the results indicated that both the 9mm and 45acp rounds were more lethal than a 55gr FMJ .223 round after passing through 3 simulated walls. The high velocity lightweight bullet started to tear up and lose energy sooner than the two handgun rounds.