Normal bullets do not do that as far as I remember. They can chip away small pieces but they do not bring down walls. You need bigger punch.
Seeing the gameplay trailer (ps3 footage if I recall correctly) he fires away at a balcony removing a large part of the cover.
Nobody knows exactly what the destruction will be like, but in my eyes it's a very high ambition to have every weapon do a lot of destruction. The ambition did kill it seeing how they remove a lot of it in 64 player maps.
Rather had the BC2 system where only explosives would level buildings (and not one rocket per building, as the sniper trailer suggested).
If they just ease the destruction in that way maybe the complete leveling of the maps can be also sufficiently diminished to keep playable 64-player matches.