1918 Buffalo, Extremely Rusted Die.

Looks like a heavily worn die. The die deteriorates (abrades) away with continued use. Thus the deterioration of the field/devices area on the coin. Heavy die wear is common through several years of coins made as the mint wanted to get their money worth out of their dies. (pun intended) The reason the reverse die looks normal is that the die was probably replaced and with a better one that was used on the obverse.
Here is an example of a Cent that was over used from the same time period.

I don't rust had that much to do with as just plain die wear.

MorgansRmine,
I would have to concur with your conclusion of rusted dies, that is alot of pitting

Hi,
What does the reverse of the coin look like? If it is the same, I don't think it would be a severely rusted die scenario.

Can we see a picture of the reverse.

Thanks,
Bill

Hi,

I wish I could see this one close up, My gut says that the coin was cleaned, perhaps harshly and that the cleaning removed a layer of corrosion from the obverse that resulted in the pitted surface.

Imagine the surface of the 1914/13 nickel in another post on these forums and now imagine the layer of corrosion having been removed. It would leave cleaned areas where bumps and depressions would be visible.

I can't be 100% sure from the pictures alone but I have reservations about the rusted die diagnosis:-)

It could be but I just see too many signs of a cleaning.

Thanks,
Bill