.458Win., member here, has been very happy with his .458Win.Mag. as a stopping rifle for backup when hunting the worlds biggest bears in Alaska.

Surprised he hasn't chimed in here in this thread, however this thread seems to run about once a year or so.

Personally, I've never had a .458Win Mag, however I have had a .458Alaskan (my name for this wildcat) which has about 4-7gr. more capacity than Winchester's version.

When using Banes .458Win. Mag. data for my loads, my 24" bl. duplicated the velocities Barnes gave for their test rifle, also24" iirc. Perhaps my seating depth had something to due with my rifle giving higher velocities than I thought I would get, or simply our rifles developed similar pressures and speeds with the same loads.

My .458 Alaskan case was the .450 Alaskan which is a necked and blown out .348 Win.Case. I simply turned the rim to .532" and cut a new extractor groove so they'd work in a normal magnum bolt and action.

Case feed also worked fine although the original rifle was a Winchester M70 in .264Win.,Mag. with it's ridiculous 22" bl.

I simply re-barreled it to a Shilen barrel I had and chambered that .458 barrel with my .450 Alaskan reamer.

That was the rifle that finished off my shoulder cartilage to the point I could not shoot any CF guns for a year.