Doug, on page 14 of Reese's Luger Tips he says that a .30 cal Springfield barrel can be made into .30 Luger barrels. The Luger bore diameter is .301 and the Springfield is .300 to .301. Both barrels are v-thread, right hand, and 20 threads to the inch. Also advised only for an expert gunsmith. This may be a way to go for you. There sould be plenty of steel there to make most any kind of barrel you want. Here is a picture of my custom barreled 1916 .30 cal.
