I have one that bounces around in the pickup all the time, great sight. I've removed it probably 20 times and swapped different optics on mine, and it always returns to zero. Great sight, but like bigcountry said, hard to shoot really tight groups with it. Not a problem to keep the bullets in a human torso though. I've shot quite a few coyotes/jackrabbits with mine on the run, great sight for that.