I have had a lot of .458 Winchesters and reviewed others over the years and learned many loads that work well on deer sized game.
Using the 300gn Hornady I like the following;
71gn of Rel 7 for 2386fps
69gn of IMR 4198 for 2514fps
74gn H 4198 for 2585fps
Barnes makes a 300gn X bullet for the 45/70. Try the following;
75gn H 4198 for 2640fps
78gn H 322 for 2534fps ( This load shoots under MOA in my current .458)
There is a wonderful 350gn Barnes TSX which is a great all round bullet for US hunting.
I have used H 4198, VARGET,, AA2230 and H 322 and all shoot well. Start at 70 grains and work up to a velocity between 2450 and 2500fps.
Another good bullet for Deer and up that will expand is the Woodleigh Weldcore at 400 grains.
Try 74 grains of H 322 for 2336fps
74gn of H 4198 for 2434fps
77gn of Rel 7 for 2283fps
All of these loads workd well and are accurate in the rifles I have tried. If you are using a longer barreled rifle such as the CZ 550, the velocities could be as much as 200fps higher for the same loads.
Start a few grains under my loads for the 300 and 350 grain loads please.
John
