When you have found the right load to shoot out of your gun? And you still wanna tinker and mess around with it some more, even though you get a sub 1in group at 100 steps. I was thinking of getting a new ML but financially cant at this time so i just get to look at mine and try to figure out what to do next. But it is so close to perfect I hate to mess it up. Like the post about the barrel polishing, I would love to be able to do that just to have something to do, but I am scared it may make my accuracy fall.