I see where Barnes makes both 300gr and 250gr X bullets in .458" which are designed for lever actions.
Anyone have any experiance with either bullet in the Guide Gun for deer to elk sized game?

I found typical 300 gr jacketed bullets too fragile for my liking on deer and certainly wouldn't suggest them for bigger than deer sized game.I switched to the 300 Nosler [Win Partition factory load] and was much happier with expansion and penetration.From all I've read the 300 Barnes and 300 Partition perform the same and are suitable for elk etc.If you think a 300 is too light there is also the PMC 350 load.

Mete,

The Partition was also a consideration. I appreciate the input as I'm working up a load for my wife to use in her GG. Up to now she's only used a loaded down 400gr commercial cast bullet (which worked for her one and only deer).

I have Barnes making for the 475 Turnbull 350 and 400 gr TSX with a .345" meplat as well as 400 and 450 gr soids. Hawk bullet madse up 400 gr .035 jacket .475 bullets with the cannalure .500 from hte nose too.