I own a 458wm Marcel Thys sidelock. I bought the rifle at a price that would allow rechambering to 450NE 3 1/4" and reproofing and still leave considerable room compared to the same rifle, or one similar, originally chambered for a comparable rimmed cartridge. (this rechambering is, according to JJ, the most suitable for just about any rifle originally chambered for 458wm, since the action width of the typical 458wm double does not suit 450NE #2 etc)

I would shoot, without hesitation, a rifle rechambered by JJ, even without reproof. Not so someone I don't know. But I would reproove my rifle if I had it rechambered. I would buy a rechambered, but unprooved, rifle subject to reproof or at a significant discount without contingency.

One thing to keep in mind is that if you find the otherwise right rifle but in 458wm, it may be discounted a whole lot more for the calibre than the worst case cost of rechambering, reregulation, reblueing and reproofing. Mine was. Worst case cost last I talked to JJ and best I recall was about $1700. The chambering in 458wm also gives you a significant bargaining point, and the owner might be sensative to it.

I buy what I like and don't sell too much. Still, I hate thinking I'm in the red, too much at least. I think it takes quite a nice rifle to make a rechambering even begin to make sense. But, as I've said before, if my rifle had been in 470NE, I probably could not have afforded it.

By the way my rifle has performed flawlessly as a 458wm.

My 2 cents worth.

JPK