I'm stepping up the grade of 99s I collect, as I have plenty of shooters, hunters and decent/ok ones. So, I'd like to get a better education about the different bluing that was used from say around 1900 to 1960. I thought they'd be the same, but have seen members eluding to it changing multiple times during this period. Do any of you know how many times the bluing changed? Pictures of the finishes on high condition guns would be great, but that seems like a lot of effort.

Thanks.

David Royal's book would be your best resource here.

Up to WWI - a dark, mirror blue on receiver. Actually shows up again briefly around SN 300,000 on some 99's - not all. After that there are some differences, but they are all more of a standard blue you see on rifles.

Early mirror blue:

Thanks for the response.

This is a good example of why I'm asking. If I saw that gun on a table I might assume it had been refinished at some point ( I'm not saying it was ). I'm not an expert but I've rust blued around 10 guns plus a handful of shotgun barrels and the only time I've seen the mirror like finish is when I used 600 grit or above sandpaper on the metal. I have 11 1899s from 1901 to 1925 with anywhere from 60% to 80% bluing left on them and none of them have a finish like that. Maybe it's just over the years they dulled, or did the more fancy guns like the one in the picture get a higher polish on them?

Every 1899 up through 1917 had a finish like that when it was new. You can usually see remnants of it with guns having original bluing, even if it's gone to patina or similar on most of the receiver. The 1895's as well. That one just shows it really well because it's lost almost none of the finish.

It's hard to get a picture showing how much of a mirror finish they had.

Here's an early 1899C that has a lot of original finish left, but the loss in spots makes it less obvious it was a mirror finish.

Is that really true?
I've got a #153xxx that is obviously mirror blue. Some under and some over that are nice but not mirror.
???

To the best of my knowledge, yes..

The engraved picture really highlights the mirror blue, but I've seen everything from plain jane 1899A's to SR's to SRC's to 1899H's to 250-3000's that all have it.

Others that weren't stored as well that have had the blue start turning to "patina".

If I'm wrong, somebody correct me..

I don't know that it's terribly important to attempt to identify how many different variations of bluing there were over the years, just be aware that there were variations. Same for 1907/15/17 pistols.
A practiced eye can tell whether or not the blue is original and also an approximate level of remaining blue. 80%, 90%, etc.

To the OP, "stepping up the grade (condition)" and "blue variations" are two different things.
A person can step up the quality of any rifle model regardless of the blue variation and many options will be available.
A person can focus on mirror blue or deep blue variations and very few options will be available.
Pick you poison. We all do.

It is easy to tell if something has recently been refinished. In the scenario of someone doing a good reblue in say the 1950s or 1960s it may be more difficult to detect. Also there are people who are skilled at refinishing them to look close to original. The more expensive and desirable the gun, the better chances of someone being dishonest. So having an idea of what the finish should look like would be helpful. I think the more education one can have about what you're purchasing is a very good idea, especially on higher dollar guns. In my opinion anyway.