RE: sighted in my 7mm rem mag. got a ?
If your not getting it on paper at 100 yards move back to 50 yards and zero it at that point and then move to 100 yards. You can get a trajectory table from the manufacturer of your ammunition in fact most are printed on the ammunition box. Bear in mind a lot of factory ammo is underloaded and doesn't match advertised velocity. This is just a guideline..too many variables in place to predict point of impact at ranges beyond 200 yards. Temperature,Humidity, Weather, condition of firearm etc etc. Generally using any high velocity magnum with pointed bullets if you are 1.5-2.0 at 100 yards you'll be within a couple of inches of point of aim at 200 but no guarantee on that either. As other's have suggested you must shoot targets at the distances you plan on shooting game to deteremine POI.