The weight of a bat can actually makes the biggest difference of all from a strength standpoint. I say CAN make the biggest difference for a reason. The density of any given species of wood does slightly vary up and down. This basically means that if you have 10 pieces of wood that are all the same species, the same size, and the same moisture content, they will all vary in weight. This is the reason that we can make any given bat model in several different weights without changing a thing on the shape of the bat. For example, for Model A if we are making a 33 inch 30 ounce bat, say it will take a 90 ounce billet (what the wood is called before it is turned into a bat) to hit the targeted 30 ounces. If we wanted to make a 33 inch 29 ounce bat we will have to use a lighter billet, maybe an 88 ounce billet. Every model will be different, depending on the design of the bat. Where you have problems is when you use the wood that is at the extreme light end of the scale for that species. Those billets have the lowest density in the range for that species, and are not as strong. This is what I was referring to earlier when I said usually the bigger the barrel the weaker the bat. It all depends on your targeted weight for the bat. As an example, if you have a 33 inch bat that has a 2.5 inch diameter barrel and your targeted weight is 30 ounces, we’ll say it will take a 93 ounce billet to hit that targeted weight. Take that same bat, but make the barrel 2 5/8 inch diameter. Now to hit your targeted weight of 30 ounces, you have to use a much lighter billet, maybe an 87 ounce billet. That lighter billet is not as strong as the one you used to make the bat with the 2.5 inch diameter barrel. Even though the bat is bigger, it is not as strong because the density of the wood is lower. Now take the 2 5/8 barrel bat, and use the 93 ounce billet. Now the bat will be stronger than the 2.5 inch barrel bat, because the density of the wood is the same, and there is more mass in the 2 5/8 inch barrel, but the finished bat may end up weighing 36 ounces!icture of a maple billet--**
Over time the weight of a bat can change. It is usually not even noticed as the bat will most often break before it has a chance to gain weight. It primarily depends on the environment the bat is kept in. In very humid climates, it is possible for a finished bat to gain as much as an ounce over the course of a year. In dry climates, it may never gain any weight. The only exception is unfinished, and partially unfinished bats. If you have an unfinished or partially unfinished bat (just bare wood), it is not a matter of if it will gain weight, it’s a matter of how fast it will gain weight. Without the protection of the finish on a bat, it is basically a sponge! If you prefer unfinished bats, you must be extra careful how you use and store the bat. All it takes is a few minutes laying in damp grass, and your bat just got heavier! Unfinished bats can gain as much as an ounce a week just sitting in a semi-humid environment. Eventually the weight will level off, but it will be much heavier than it was when you got it! Another problem with unfinished bats is warping. As wood absorbs moisture, it swells. If you leave an unfinished bat in damp or wet grass for as short as an hour or so, it may warp. What happens is one side of the bat is getting wet and absorbing moisture, while the other side remains dry. The wet side of the bat begins to swell, and pretty soon your prized bat resembles a banana!