550 yards is the longest I have taken. I would go maybe 600 on an animal the size of an elk, and about 450 to 500 on deer. Everything has to be just right though or you can be just pi$$ing in the wind. The long shot imo should be done in the morning or at least several hours before dark so you will have good light to find the critter or to make sure you missed if thats the case. I also think that if you havent shot at targets over the same ranges then you should never try it. Just knowing what a loading manual says about trajectory and wind drift isnt enough. You should have some actual experience shooting at long ranges rather than just thinking because your rifle will launch a bullet at escape velocity you can kill anything you can see. A rest, a good laser rangefinder, a deer that will stand still in the open on a calm day, and a confirmed zero with a highly accurate rifle is what you need to start with. Go out and burn about 1500 rounds a year with that rig over extended and different ranges, and your chances get much better. I passed shots at a good whitetail last fall at ranges between about 280 to 350 yards because he wouldnt give me a good shot. I think I could have killed him, but just wouldnt try a low percentage shot. I took a doe at over 400 yds on that same powerline right of way. Once you get yourself and your rifle ready, there still wont be that many opportunities. At least not where I hunt. But, I think you should be ready if the chance comes along.