Ball nose bits and surface finish

Greetings folks!

I’m new to wood carving and ball nose bits, and I’m having a really hard time figuring out where the point of diminishing returns is with respect to minimal cusp height, step down and step over settings. The model I’m working with is a western revolver at 1:1 aspect. Based on personal experience, are there any general rules of thumb and recommendations on carving this on walnut without it taking several hours yet result in a hardly noticeable cusp? I’d appreciate any advice, thanks!

Usually when doing a 3D model you use a 1/4" end mill with a 40 percent stepover for the roughing. When it comes to the ball nose bits the finer the detail the smaller the Ball nose bit. In your case I would suggest an 1/8" ball Nose with a 10 to 12 percent stepover, then a 1/16" Ball Nose for the detail with an 8 percent stepover for the finer detail in the handle. If you’re using the Vectric software you can include both bits in the finishing toolpath.