Recently invested in KPL and KPL Heavy, aplied them to my knives, and really didn't notice any difference in action quality. Maybe some "sandiness" has decreased, but really nothing significant, only marginal. So, a few questions, just to make sure my understanding is correct... When an action is "sandy" or "scratchy": What is this? What causes this? I have a few knives that are very "gritty" (when you move the action open and closed, you hear it), but still offer a good action. Whereas I have a ZT that literally feels like polished glass riding on polished glass. Makes no noise, no friction. Is the "sandy" sound / feeling inherently good / bad? Can it be made to mimic the ZT's "glassy" action? If so, how? Regarding lubrication: Is wet the best? Dry the best? Difference in optimization in different action systems (bearings vs washers)? I know "the best" is often subjective and inherently has a "it depends" kind of answer... but if I add the restriction of optimizing action, maybe that helps answer the question. For what it's worth, my favorite actions have bearings, and that's what in most of my knives. How to modify a knife to make an action better without sacrificing centering / lock rock? I know you can bend the lockbar backwards to reduce tension... but every time I've done this, I've introduced some form of lock rock. No bueno. I know you can loosen the pivot, but this often sacrifices blade centering and often introduces horizontal blade play. No bueno. What else can I do here? I've heard of some people finding success "polishing" certain parts of the tang... either the bearing races or the detent track. Anything else?