I don't know what you will be shooting at 1000 yds. but if it is a target just think of how the bullseye will look through no magnification at 100yds., or rather put up a target at 100 just to see what you will be seeing at 1000. If you have young eyes and are talking big game 10X is probably enough. I have shot medium sized does at 600 with a 4X but I was a lot younger then and wouldn't consider it now. There was a time I could shoot a good military surplus rifle with original iron sights right along side my brothers scoped remingtion shot for shot at 400 but not now. Also, it is a matter of choice and personal wants and needs. If you are wanting to hit small targets/objects at this distance I would recommend higher magnification.