I was looking through a reprint of a Sears catalog and it listed ".30 Government" in the ammunition section.
An 1899 edition of the catalog, so it had to mean .30-40. .30-30 is listed as .30 Winchester Centerfire.
I've got a book showing a Winchester add on one page talking about the Model 54 listing it in .30 Gov't and .30-40, not sure what year that ad is from.
Willard's Winchester Model 70 is stamped ".30 Gov't 06" for the caliber.
I like how .30 Government changes as the years change. I'll bet if we hadn't gone metric with 7.62x51mm NATO, it'd be .30 Gov't too!
I noticed something like this before.
Colt 45 can mean either an M1873 revolver or an M1911 pistol (or Billy Dee Williams' favorite malt-beverage).