Scopes and mounts can be unpredictable. I know of folks that have dropped their rifle from their treestand and the scope was still dead-nuts on. I also know folks who had to (unexpectedly) sight-in again on a rifle that was always right-on for years. They had no clue what could have happened to the scope. I also have a Leupold scope and if I dropped it from 20 feet, I would be amazed if it still shoots straight....