In a nut shell that's basically it. It smooths out the bore, so if your grooves or rifling that looks like this:They sell some fire lapping kits on this site that seem very user friendly. It's a way to remove factory machining marks from your barrel which in turn reduces lead and copper build-up?? There are others here that may correct me and for sure give you a more detailed explanation. They will probably refer you to another thread that has already covered this.