Another bullet in 458 that has a very high advertised BC (.389) is the Barnes Original 400gr SSP. I like the BOs but ive found them to expand better with more fps. I wouldn't even shoot the 300gr BO SSP in my Savage unless the load was good for at least 2150fps. Preferably 2300fps to get the most long range benefit.

It will expand fine with much less fps than that but was happens at 300 yards where that BC has some real value.

I have shot a few 400gr bullets in my 54cal but nothing intended for long range. The 1-28 did stabilize them enough for close range work. They THUMP on both ends with max loads. The 385gr ive shot with 120grV of BH209 is very unpleasant on the bench in such a light rifle.

I wish i had a 54cal with a longer barrel and faster twist to try the Rem 50cal 385gr at longer distances. Its BC isnt anything stellar but its pretty good for a 50cal.

I really hate it when i agree with TB.

BTW Rocky Mountain bullets makes a .458 310gr for smokelessmz.com. Its very very similar to a Parker Match Hunter with a similar $2each price tag. BC is very high (.430) for a bullet of this caliber and weight.