The only "zero stop" I know of is on Nightforce scopes. A zero reset isn't the same. Most quality scopes, like Leupold, have set screws on the elevation knob that allows one to turn the dial to a "0" position, but that's only a reference point. You can still turn up or down and need to have a way to get back to the zero you set. NF zero stop is set and once you set it, you can only go up from it. I usually set mine at 100 yards with one inch of down available for changes in altitudes.
Swarovski scopes do make a re-setable turret that can be set for several yardages and will be repeatable. Both NF and Swarovski are both high end scopes.
