Wood..or Metal

Due to the inexact nature of wood, you can't gauge the weight of a bat by the model #. Louisville, for example, will only allow you to order by length. The differential will vary due to the density of the ash. I run a wood bat collegiate league and order 100's of bats from different manufacturers every year. That being said, any time you start to see length/weight deltas growing beyond 2, you are compromising the integrity of the wood. Simply stated, the higher the delta, the lower the quality of the wood. Cupping will take some weight off the end of the bat, but will generally only be around .5 oz. Of course if you have a real dense (heavy) piece of ash, it will be higher. The point I'm making here is that if you are looking for a -4 or -5 bat, don't waste your time buying wood. You're just trying to incorporate the inherent nature of alloys into wood. Apples vs. oranges. Anyone offering bats with those deltas is sacrificing either quality of wood, outer diameter, or both. A good hard piece of ash is going to be -2 at best. Start working on those hitting drills and learn how to use your hands correctly.