The savage 250-3000 rifle and round was not introduced until 1915 or so.
The savage 250 model 99 was made up until about mid 1980's
The 3000 stood for 3000 fps. it was the first commercial round to do so. But they had to put a lighter weight bullet in it to get it to do so. ( If I remember it was 87 grain)
The savage 99 went from the lever safety to the tang safety a little after the 1,000,000 serial number. This was after ww2.
Very late in life they got rid of the rotary built in feed and went to a magazine based rifle.
The 1899 dates are the patent dates and also the model.
for a while it was known as the model 1899 rifle, and then later it became known as the model 99.
If you get me a serial number ( with the last 2 or 3 digits x'ed out) I will find a production date. Look all over very carefully, there should be some letters stamped into it somewhere. A, F, E etc.
My dad gave me a 250 savage 99 for my 16th birthday. It got destroyed in a freak accident and Ive been trying to replace it every since. As a teenager I shot quite a few large hogs with it with very good results.
These are going for fairly high dollars now.