http://cg.tutsplus.com/tutorials/maxon-cinema-4d/construct-a-detailed-type-97-hand-grenade-in-cinema-4d-bodypaint-and-photoshop-day-2/

In this two part video tutorial, you will go through the complete process of modeling, unwrapping, and texturing a Type 97 hand grenade, the standard fragmentation grenade that was used by the Imperial Japanese Army in WWII. In the first part, you learned how to create the model using the lathe and boole functions in C4D, and now you will learn how to unwrap it in BodyPaint and paint the texture maps in Photoshop.