I found this at the following url: http://www.cordite.com/wwwboard/messages/211.html
The 30-338 is very similar to the 308 Norma Mag if memeory serves me correctly. I believe you'll find it to be a "custom only" item. The Montana Rifleman lists the 30-338 as an available caliber. Rebarreling an existing rifle might be an option.
>>>>>>>>>>>The 30-338 is similar to the 308 Norma Magnum, but there are differences. The 308 NM case is slightly longer and the shoulder is slightly farther forward. If 338 brass is used to make 308 or 358 Norma Mags, the cases will be a bit short and the shoulder will have to be fireformed forward. However, all this isn't really necessary as brass for both, as well as loaded ammo, is available from Norma. By the way, the 308 Norma is generally accepted as the most intrinsicly accurate of all the 300 magnums. Add this to the fact that the 3o-338 is a wildcat with no factory ammo or brass available, and you might want to consider the 308 Norma. It will fit in any action that will house the 30-338.
Thought this was interesting, Ken