.318WR barrels are available on special order from Lothar Walther. They also list the reamer. No idea as to cost.

Like rigbymaser I also would like correctly headstamped brass for my overseas trips. In brisbane last month I got the third degree about my rifle and ammo, coming in and leaving. My limited dealings with Bertram reveal new brass is not as easy as just placing an order.

Either project is not going to be cheap but I agree with rigbymauser, these calibres are about following the dream ( and in my case one upmanship ) not worrying about cost. Otherwise you may as well just wildcat the .30-06 case.

Edit: All the three cartridges .30-06 (with heavy projectiles) .318WR and .333 Jeffrey I'd expect to provide similar performance in the field.