Congrats, nice rifle, especially with the pad and grip cap and refinishing you have in mind.

How long are the barrels on your rifle? This will impact any decision on rechambering, especially since the 458wm likes longer barrels for top performance.

Regarding any thought soyu have on rechambering:

DON'T RECHAMBER TO THE LOTT!!! There is nothing to be gained and much to be risked going this route, imo.

Before any consideration regarding rechambering, you really need to develop a load that shoots to your rifle's regulation first. I have found sevearl loads that make 500gr bullets regulate at velocities between 2050fps and 2145fps. 2145fps is plenty sufficient for elephant bulls, which are most demanding of penetration. Powders which have proven helpful with 500gr Woodleighs are AA 2230 - best in my rifle, H 4895, Varget, H335.

I noticed no benefit and little difference at all trying 480gr Woodleighs so abandoned that effert. The Woodleigh 480's also eat powder room because of the rearward location og the cannelure.

For 450grNorth Fork flat nose solids, H4895 works well as does AA2230, but I am going to try a couple of different powders like H335. The North Fork flat nose solids give astounging penetration as lower muzzle energy figures. I shoot the 450's at ~2200fps and their performance is remarkable.

Once you find out how your rifle shoots as a 458wm you may find accuracy and velocity are where you want them to be. IMO, velocity from 2000fps up is fine for buff, but for elephants you want 2100fps or better. If you find your rifle shooting the 500's at 2100fps or so, hopefully better, then shoot it a lot to see if there are any extraction or ejection issues. To try to make my 458wm double fail, I left the chambers and ejection system dirty for more than 200 rounds and could find no fault. I suggest a symilar test, you are trying to creat a situation where any trouble will come to light.

If you rifle passes the test of trying to make it fail to extract or eject perfectly, every time, leave it alone!

And then try some Federal ammo just to see how it will shoot should you find yourself in Africa and your ammo soewhwere else.

(My rifle shoots the slower than my handload 500 Trophy Bonded Sledgehammer solids at 2090fps about an inch lower than my loads and crossing by about 5"'s or so, which is still sufficient to hunt elephants up close and buff to maybe 75yds if that is the ammo I'm stuck with.)

If your rifle isn't well regulated or won't provide flawless extraction and ejection, or you can't find a 458wm that gives adequate performance, then rechambering might be the course of action to take.

The 450NE 3 1/4" reamer will clean up the 458wm chamber while leaving the most steel at the chambers and so this is the logical choice. Also Hornaday is making cases and is now or shortly will be providing loaded ammo. The logical resolution, if rechambering is nessescary is to go with the 450NE 3 1/4" chambers and the reregulate, if required, with the Hotnaday factory load.

When I was looking at rechambering I was told that a rechambering brings a 50/50 risk of needed to reregulate and reregulating brings a 50/50 chance of needing to reblack the barrels. JJ Perodeau's quote - from maybe four or five years ago - was about $600 for rechambering and ejector work, $600 for reregulation and $600 for reblack.

BTW, my rifle is still going strong after maybe 850 round through it, with no signs of looseness and no isnstance of any trouble with extraction or ejection.

Here is a tip for case preparation for ammo you will use for dangerous game: With a wheel mounted buffer, carefull knock off the 90* angle on the front edge of the belt on the 458wm cases. The cartridge headspaces on the belt so only round off the edge of the angle, without involving the front flat of the belt. Done right, your ammo will drop right into the chamber and not need to be pushed in over the paw which engages the rim. Works well in my rifle.

Hope this helps!

JPK