I think experience with your own equipment, if you'll excuse the expression, is the best guide. I have personally seen both ends of the spectrum, but can say I have full confidence in my current setups. If the scopes aren't broken I trust they are still on. This would be with VX3i and Burris signature zees. I have broken my fall on rock with the turrets and not seen a zero shift. I try not to baby my rifles throughout the year while practicing, this should show any issues before crunch time.
