I wouldn't waste the time and money, Mike.

Under and oversized bores are way more common than most think, and standard ammo is regularly fired in them all. One of my double rifles is .0035" undersized in the groove, and shoots fine with standard diameter jacketed bullets with no issues. While I do size down off the rack jacketed bullets for it now, it doesn't seem to make a dime's worth of difference. I wouldn't mess with sizing down jacketed bullets for an .002" difference.

When Hornady was working up their new .450/.400 3" Nitro Express factory ammo, they were worried about this because there are quite a few .408" rifles out there, and CIP standard today is .410". So, they made up a .408" pressure barrel and tested .410" jacketed bullets in it. The difference in pressure was something like 600 PSI.

Standard .458" lead core jacketed bullets will be fine, just stay away from monos.