I have come across a Pre 64winchester in .338 win mag. I believe it is an Alaskan model. The serial number the best I can tell puts it at a 1956 possible 1957 production. Serial number 393xxx but .338 win mag didn't come out until 1958. I have no reason to believe it was re-barreled, but that seems to be the case. Its a family members and they have owned it since new and say its all original.