Airsoft Action Quake
Airsoft Action Quake is a mod that replaces all bullets in Action Quake 2 with 6mm airsoft BBs as well as proper BB ballistics and sounds. Furthermore, this mod includes the NewLTK AI. Be warned though, one single hit is enough for you to be "out"!
NOTE: You need Quake 2 as well as the Action Quake 2 mod already installed before installing this.
You can download it here.