Originally Posted by postban

Thanks Bill,
The top serrations are for one hand racking on any surface. Design intent was to grab on a pants leg but also pretty much anything else. It grabs and allows you to manipulate the slide. It was refinished in the exact same finish the factory uses too. You can also you the rear sight to rack but it is a little more fine motor to line it up with your belt or whatever.
The side front serrations are to aid "press checking" to ensure state of load.