The Sierra 65 gr. Gameking BTSP has always given me excellent accuracy in four different rifles. I've taken 3 deer with it, the longest being around 190 yards.
It also behaves like a big game bullet.
This echoes my experience with the exception that my furthest WT killed was a shade over 300 yards.
Shoots well for me in 7, 8, and 9 twist rifles.