For what it is worth I have three. Last year I took one to Namibia for plains game and to experiment with some hot loads. 60gr of H4198 and Hornady 350gr JFP and some 330gr Barnes Banded Solids for the 458 SOCOM. Both loads chrono at 2395-2405fps and to the same POA at 100yds. Both loads are in the heart of the 458 Win Mag load data.
330gr BBS passed end to end through an average sized zebra and the 350gr hit gemsbok like a freight train. One was a frontal chest at about 40yds and it knocked him back and down on his haunches and then down. Didn't recover it - it was buried somewhere deep in the intestines.
Over on the AR forum, under the Big Bore section and under Terminal Bullet Performance the 330gr BBS, from a 458 Win Mag at 2300fps drove through 64" of wet newsprint dead straight.
One of them is going again this year along with a newly acquired Pre-64 Win Mod 70 in 450 Marlin loaded with 350gr JFPs and 330gr BBS.
Not sure if I would do anything different with yours - In fact I am going to be selling my 375 H&H and 458 Win Mag this year as I don't see any reason for them any more.
