800 yards with a hunting bullet could well be a iffy situation. The velocity will have deteriorated significantly by then and it may not expand.

We did Doplar Radar plotting of bullets at long range and one of the spitzer pointed soft point designs redesigned to a round nose in flight when it passed 600 yards.

I think I would look at a Sierra 175 Gr. Matchking bullet which is the same bullet used in M118 Long Range ammo which is the designated round for the M24 Rifle.

Those tourists the Marine sniper teams that totally surrounded in Fallujah and opened up on them sure did not like them.

I know if I ever build another 300 Win Mag 1000 yard rifle it will be loaded with 175s.