I know I speak heresy to the Campfire TSX mindset but I have used the 165 grain Sierra BTSP to whack a bunch of deer with both the .300 Winny and the .300 Roy.
In fact, I have a bone stock Weatherby Vanguard Synthetic in .300 Wby I am going to use some this year for deer. I'm running 87.0 grains of Ramshot Magnum with the 165 Sierra for around 3150 fps and 3/4 inch groups.