Crow, chucks, and varmints...hummmm bullet needs to expand on impact.

To 600 yards, I would go a 6mm Rem AI, shoot the 75g V max at 3800 to 3900. If the varmints ain't a fly'en, I am not to interested.

Lots of bullets just zip right through a chuck and they just crawl or run off.

You need a flat shooting round...period.

800 yards on varmints is not like 800 yards on a steel plate.