Well, I just sold my 300 win mag rifle but still have a few thousand pieces of brass for it. Today I was thinking about doing a barrel for a Savage long action by starting with a .375 barrel, cut the body with a 338 win mag reamer, then use a .375 neck and throater to cut a neck long enough to use full length 300 win mag brass. Cases would be easy - full length size with a 338 die, and fireform. After that turn the necks to cleanup, and use a Wilson bushing die to load. I'm sure this has been done before since it's so obvious, does anybody know if it has a name? It ought to make a pretty good blaster and it'll be fun to see how close to 375 H&H performance I could get.