Longest shot ever was 425 yds (paced) back in 90. Buck antelope, with a Ruger M77, 7mm RM, 2 1/2x10x40 B&L, shooting a 120 gr Speer handload. Prone off my day pack. No range finder, I estimated him at 450 yds. 10-15 mph crosswind, put the crosshairs just above his nose. Bang-flop, hit him in the neck just in front of the top of the shoulder hoping for the boiler room.
In the last year, a doe antelope 300 yds in an alphalpha field, prone off my day pack. Bang-flop. Sako 300 WSM shooting Fed 180 SP's. I was using those bullets because they happened to be the last load of several, including handloads, that I tried in an unsuccessful attempt to find a bullet/load that would shoot in that rifle. Still don't know if it's the rifle or the rings. Had a 400 yd follow up shot on another doe, but wasn't confident enough in the rifles performance beyond 300 yds.
Had numerous opportunits this past season on long shots for antelope, deer and elk at most any range imaginable. Hopefully next season, my equipement will be up to speed as well as my proficiency for some longer shots. There should be plenty of opportunities. I've been learning a lot here, and I sure would like to put it to use.