If you want someone to help you you are going to have to give enough information. You didn't say whether it was zombies or multiplayer, or whether you wanted to add this mod to your server or private match. There is a mod called BO2 Reimagined for zombies mode that I'm pretty sure reduces the recoil on the hamr as one of its many changes, but if you just wanted the recoil change you'll have to make your own mod.
