Looks like
Dia. Weight Desc. S.D. B.C. Cat. #
.308" 168 gr TSX BT .253 .476 30844
.308" 180 gr TSX BT .271 .552 30846
.308" 200 gr TSX FB .301 .550 30848
(Move 15 calibers up and you actually lose BC)

.458" 450 gr TSX FB .306 .488 45819
.458" 500 gr TSX FB .341 .526 45821

(Move 5 calibers up and BC doubles)
.510" 750 gr. Solid .412 1.070 510750
.510" 750 gr. Solid .412 1.070 510750A

Yes 458 cal bullets have low BCs, and with the low velocities they can be pushed, ballistics are sad.

On another note, ask yourself.

Does a gun that packs 75-85 pounds of recoil in a 10 pound rifle lead to high levels of accuracy?

Does a gun that is good for close range (possibly defense from bear or lion hellbent on having you for lunch) set up with no scope or a 1-4x scope, lead to precise shot placement at long range?

Is a setup for long range elk or plains game going to be efficient in the alaskan or african bush?