I love the warning thing. "If you can't hit the phone book..........."
I was going to say that whatever you use, be sure that you have a safe zone behind the target even more than you would for field points. Also, watch the target and arrow penetration. As the arrows start to pentrate deeper, that means you're punching out more of the target given you're using the same bow etc. At some point, they will go thru. As soon as that first broadhead poke out the back, it's time for a new target.
BTW, the carpet and phone books work great.
I made a stack of phone books a few times, so that you're shooting into the edge of the book not the cover, and that means you have about 8" depth. this works really well and the broadheads come out pretty easily.
Good luck
sam