You can by sanding cloth, like that used in gunsmithing. Put it under the amature bar while it is depressed (or perhaps only slightly melancholy) and pull it out, after doing this a few times, you'll notice that you're getting a much more flush strike. If you cut your own springs, you'll notice that many times everything else is perfect but the damn spring might twist slightly, for some guys this is a deal breaker, for some not. The machine will definitely run smoother the closer you get your tolerances on such things as spring compression, coil clearance, and the like. Luck to you.