Seeing that the last Rem700 rifle in 8mm Magnum was produced/ manufactured in 1998, that being the "Classic" model of which they did one particular chambering per year with that model, the Classic line has been discontinued. I imagine one would be hard pressed to find a factory barrel to replace it, which leaves the only option of having a new barrel spun up for it. In that case one would have to be very fond of the cartridge due to the fact there are many modern non belted chamberings now that match or flat out perform the 8mm Magnum. Depending on the barrel and smith your looking at 400.00-600.00 to rebarrel it. I imagine if one looked hard enough they could find another complete rifle for close to that in used condition.
The other choice would be to just throw another factory barrel on it, in a magnum chambering, I have a new unfired 26" matte, sporter weight Rem700 barrel chambered in .300 Ultra magnum if that's the direction you want to go in. Just another option, I would cut you a smoking deal.
