Mike-
Nice rifle.
If it fits you properly it shouldn't be a challenge to shoot.
Hot .338 loads have a lot more slap than .458 loads (whiz-bang recoil calculators be dammned!).
My .458 is somewhat similar, but with a classic brit sporting stock, no monte carlo treatment, no scope mounts, and it weighs a little more than what you have there.
I shoot mine a lot. My hunting load is a 350gr hornady SNRN at 2450fps. Recoil is somewhat brisk, still either this load or 500gr at 2100fps doesn't bother me a bit.
My rifle is very accurate too, and every properly sorted .458 I've come across has been accurate.
If you got a good deal on it, keep it for a while and run it a bit before you decide to jump on the 'big bad scary .458' bandwagon.
Write me if you'd like some load data advice.
We can cover that via email or on the phone.
The cartridge isn't the ultimate punisher that many people say it is, especially if you're shooting it in a rifle that fits.
Just don't treat it like a bench rest rig or long range sniper system. Shoot it from hunting positions, do your load development at a standing rest, practice with it when you can.
Set up right, a good .458 Mauser is a wonderful thing and definitely has a place in the North American Hunter's toolkit.
I took mine out on a Black Bear hunt this winter, and have been feeding my family bear meat since!
--Tinker
