It works this way, if you check the zero after it's bumped it'll always be perfect. I have had two bad ones, had an old leather sling break years ago when I was going up the stairs from my dad's basement, went down 11 stairsteps and landed on the concrete basement floor. I went promptly outside, laid it over my truck hood and evaporated about a 4 in dirt clod at 200. I also had a rifle slide off my shoulder when climbing down off a rockpile to start a stalk, hit a rock hard enough to dent the bell of the scope about a quarter inch in and an inch in diameter. Killed the zebra with one shot. I checked it later, it was perfect and hunted with it for a week. The dent is still there!
