I've used a .308 and a 7mm-08 on the 800 metre range. They are both amazing at that distance, both for what they can and can't do. Both rifles equipped with 26" barrels were still supersonic at that range. With the rigs sighted in at 100 yards, as I recall it was 97 clicks up on the elevation turret in order to be at the correct elevation for 800 metres. That's near 25 MOA ABOVE a 100 metre sight in aiming point. At 800 metres, that is effectively shooting a rainbow, which arcs above the line of sight by a good 25 feet at the mid point!!!!!!!!!! Think about that: the bullet is actually travelling 25 FEET ABOVE the line of sight!!!!!!

Windage was another story all together. With the ever watchful eye on the wind flags gracing the shooting range at points every 100 metres, if one were to pick shots carefully when the air was relatively still, one could stay on target eerily effectively. A tiny gust of wind equaled a clean miss on the entire life size military "enemy soldier" targets in use on that range unless one doped the wind skillfully and with a good dose of luck.

The .338 Lapua using very high BC 300 grain bullets driven at very high velocity are much more effective at bucking the wind, and do not exhibit such a rainbow like trajectory, but don't kid yourself, it's still a healthy rainbow.

I don't shoot at animals that far. It extends far outside my personal code of ethics and it indeed make me feel somewhat nauseous to watch the super long range bullshit "hunting" shows on the weekend tv, designed by all appearances at least to to me to be about selling tacti-cool rifles, and twiddle knob ultra magnification scopes, and less about good ethical hunting.

Anyhow, I believe in magnums for their properties of flattening trajectory such that when hunting, I can hold on hair even at extended ranges, for me being 400 yards or less, and preferably much less. if my rifle won't shoot flat enough to hold on hair, then I feel I am not close enough to the intended target for the particular hunting rifle/cartridge I'm carrying. There are obviously other factors at play such as bullet weight, caliber, construction, impact velocity that also need to be factored when determining suitability for the intended prey, but one still needs to hit 'em well and in a vital area in order to kill humanely, and reducing trajectory as a key consideration is important for me. I love to hunt, but I do respect the game animals, and I want to feel comfortable that when I decide to shoot at something, that I can score a fatal hit with that first shot.

My boundaries and my particular code of hunting ethics are designed by me and for me and I am comfortable with them. However, I would never expect anybody else to have to adhere to them. To each their own, and we each need to answer to ourselves at the end of the day, but I do have my own opinion about what is probably too far to ethically shoot at animals. I share it here not to lecture, but to provoke thought.