I've run most incarnations of the Sig Kilo, currently have a Kilo 2400BDX. I've ranged steel with it out to 1500 yards ( as far as my steel goes) and trees and whatnot out to 1800 yards. If you're looking for good returns on animals at 1000 yards, I'd pony up for the most powerful rangefinder you can get as conditions can wreak havoc on a LRF's performance.