Like the majority of silhouette shooters I used a Leupold, generally a 6.5-20x40, because a lot of the ranges I shot were windy and on a windy day I could turn the magnification down to lessen the apparent wobble so it wasn't so distracting.
My tracking issues went away after talking to a Leupold tech, he said that by moving the scope elevation/windage adjustments within a limited range from the zero setting and up to eleven minutes or so that eventually the grease on the threads wipes off and caused sticking in the adjustment. He advised that from time to time that the adjustments be "exercised" by runnng them from stop to stop and redistributing the grease. I started doing that and my elevation/windage adjustments worked just fine after that.
drover
