I still have one of the 1985 Rifle Articles, Phil. My .458 2" had a 3/8" freebore, which allowed me to seat bullets out a ways. I ran 2,060fps with 510gr. Winchesters & 2,200fps with 400gr. Barnes & 2,300fps with 350 Hornady RN's.
I packed it guiding, but at that time, had 520gr. RCBS cast loaded to 1,600fps. Killed a wounded 6 1/2 foot black bear and a black wolf with those loads. They worked.
The .458's (.458 2" x 2 and .458 Alaskan) tore up the cartilage in my right shoulder, fore and aft, but didn't damage the rotator cuff for some reason. Figured approx. 15,000 rounds through them total.
The .458 Alaskan on a Model 70 Winch. (.450 Alaskan recess rim and new extractor groove) did 2,250fps with 500 Hornadys. According to Donnely, it has just about 8 gr. more capacity than the .458 Winchester. I used my .450 Alaskan reamer for the chamber.
I've always felt the .458 Winchester of today, does not deserve the bad press it got from long-term hot weather temperature with the ball powders of old - 50's through 70's ammo in Africa.