I have seen things two ways.
You can go with a heavy bullet (lots of mass) moving slowly. It will go through just about anything. They also pack one hellova punch. There is a higher chance of over-penetration as well as not expanding as much.
Or, you could go lighter. Moving faster. Greater expansion. Less punch. Less chance of over penetrating. Easier recoil.
Personally, I am using these rounds in my Ruger GP100 3" barrel:
http://www.midwayusa.com/eproductpag...eitemid=686149
Yes, these are 38 Specials. But, they meet all of my requirements for a bedside gun for my wife. And she shoots them well! That is the most important thing of all!
Killjoy