You are not going to get the wound channel from coper that a good lead hunting bullet makes. Typically on ungulates I shoot with coper, the bullet petals open as designed, but the bullet pencils through, with the exit slightly larger than the entrance. So, shot placement is significantly more important. But, coper would be fine to 600. If you're going to shoot further, I would want a good lead bullet, like a Berger, as they are designed to open up at much lower volicities than coper. If you're in a state that allows both, and you have the equipment, ability and desire to shoot further, I'd have a bullet/load for both coper and lead.