In my personal experience of using ordinary 1oz slugs and buckshot in law enforcement and generally being unimpressed with their performance on barriers I would go with something else.

A couple that jump to mind are the partitions sabot slugs, the Brenneke KO or the Barnes slugs.

Federal/Barnes
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=600665

Brenneke KO
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=540197

Winchester Partition
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=150399


Hunt hard, kill clean, waste nothing and offer no apologies.

"In rifle work, group size is of some interest...but it is well to remember that a rifleman does not shoot groups, he shoots shots." Jeff Cooper