I googled but didnt come up with much anybody know of a good mod that adds weight to arrows and bolts?

Well, there's always Requiem. But you were probably looking for something simpler. There are a few different mods that do this, but I don't know much about them. Here are the links:

http://www.nexusmods.com/skyrim/mods/37816/?

http://www.nexusmods.com/skyrim/mods/28264/?

http://www.nexusmods.com/skyrim/mods/14389/?