.243 using the Sierra 85 gr. HPBT for deer

[denton]

Standard grade soft point bullets expand and work properly when the impact speed is between 2100 fps and 2800 fps. Below 2100, they do not open, and create a long, skinny wound channel. Above 2800, they open too much, too soon, and make a much shorter wound channel.

Any 85 grain bullet in a 243 is going to be going faster than 2800 fps for a fair distance past the muzzle.

Running a hollow point is going to make the too much too soon opening problem worse.

It's not that you can't kill deer with that bullet, in that caliber. You can. But if you want something reliable, heed the advice given earlier, and use 95-100 grain bullets, perferably Partitions, for deer.