After a year of searching I finally was able to verify the reason behind the 30-80 WCF cartridges.
As some of you may know, the very first 308 Winchester ammunition was unheadstamped but the boxes were labeled 30-80 WCF. It’s always been my understanding that Winchester was developing a Model 80 rifle and was intending to introduce it and the new cartridge together. But, for whatever reasons, development of the rifle was delayed and the new cartridge was introduced in October, 1952 in the Featherweight M70 as the 308 Winchester. The new rifle was later introduced as the Model 88.
Here’s a response that I received from the Winchester Museum in Cody Wyoming.
I just verified in our collection that we have 3 Model 80 prototypes - with 1 lefty. All 3 are marked .30-80 on the barrel. Sounds like proof enough!
Cody Firearms Museum[/i][/b]