I shot just over the back of the first deer this year twice. My wife said I was shooting just over its back to I droped the crosshair a tad and hit it dead center. The second one I hit on the button the first shot. I know that elevation can change the point of impact of a sighted in rifle but I quess I never realized how much. I sighted my rifle here where my wife works but where we hunt is about 2000 feet higher in elevation. With my 257 Robert sighted in about 2 1/2 inches high at 100 yds here will have me shooting 4-5 inches high down where we hunt. It happened last year to but I didn't get the message. Got it know. Got to sight in dead on here where I live. Does anyone have a rule of thumb for elevation differences?