Longest kill to date with my beloved .308 was a groundhog at 568 yards, it's actually in Kevin Kram's extended impact DVD. I shot the 208gr A-max at 2642fps from my Walker custom rifles
.308, and yes it actually did go that fast, this was Winchester brass, RL17, and chamber specially throated, since it was good enough to set an f-class national record for me, I'd say it worked!!
Also missed a whitetail doe at 764 this year by about 4" high (from
poa), windage right on, because I forgot to adjust for downhill angle... Shoot to distance was around 745... Took the hair off her back... That was with a 190 Berger VLD at 2859fps in lapua brass, also with RL17. Should have stuck to weight sorted Winchester brass, as it held up better to there hot loads than the lapua did (win has more capacity).
Barrel is toast however so it's on my wall and a fresh one is being put on as I post this. I may just have to take it out hunting for old times sake after all...