RE: .270 question
Using the numbers provided by montanavet, zeroed at 200 you would be .5" high at 50 yards.
As mentioned I would strongly encourage you to sight in at 100 yards and I perfer to fine tune my sight in at 200 yards on a gun that I might be shooting that far or further with. There can big some pretty big differences from 50 to 200 yards so the further out you can sight in at, the better.