On a recent suggestion regarding Harvester Scorpion PT Gold bullets - I was reading the blog associated there:
http://harvestermlhunter.blogspot.co...combo-for.html
And he stated that he was going to be trying .458 rounds:
One combination I am looking forward to doing more with in the future is with .458" diameter bullets, such as the 300-grain all-copper Barnes SOCOM, the 300-grain all-brass Lehigh bullet, and the 325-grain Hornady FTX. I've been loading and shooting these bullets in my Knight "Long Range Hunter", shooting 120-grains of Blackhorn 209, and have found they make hard-hitting elk combinations that shoots well under an inch at a hundred yards with regularity. While the black .50x.45 "Crush Rib" Sabot has been designed to be loaded with a .451-.452" diameter bullet, it still loads well with the .006-.007" larger diameter .458" bullet. In fact, these bullets with that sabot load easier than the "standard" sabot and .451-.452" bullet combinations I shot and hunted with for years.
(Note: When shooting the 300-grain Barnes SOCOM, I rely on the yellow .50x.45 "Crush Rib" sabot to accomodate the the slight boat-tailed base of this bullet.)
I couldn't pull up a search on the forums on .458 so wasn't sure if folks were trying this or not and how the ballistics compare .451 vs. .458 for long distance (and assuming muzzle fps is similar for similar weight bullets, regardless of diameter-"ish").