um.... man. .308 is meant for power at distance. I'd look into a frangible round, http://www.gunsamerica.com/969820707..._Frangible.htm
frangibles disintegrate when they hit a wall or other hard surface. They're not foolproof, but they minimize wall penetration when the shooter misses. They're also some of the nastiest things you can shoot someone with out there. Theyre also potentially hard to find.
If you go with frang, make sure you test em out on a range to make sure they feed well and your gun likes em before you go trusting your life with them.