You've got an earlyish Model of 1905 4th change, possibly one of the last ones made with the hard rubber stocks, which were dropped as an option in, I believe, the early 1930s.
This model is, in many ways, the definitive Military and Police, as it was the last of the pre-WW II engineering change revolvers and, when war came, provided yoeman's service not only for the United States but for many of our allies, as well.
Unfortunately, yours has seen some hard storage in that the finish is pretty thin and it appears that you have a significant amount of pitting on the barrel, but the stocks are in very nice condition with very little wear.
That indicates to me a gun that was shot little but stored in a leather holster for long periods of time.
My guess is that a look down the barrel will show strong lands and grooves and a nice shine.
The nice thing is, though, that the bluing remains blue - it hasn't gone over to the brown flaky patina that is indicative of even worse storage or even harder use. I have, IIRC (it's in the safe, I'll dig it out later) a third model made in the early 1920s that has gone all patina on me. It is mechanically very nice, but it looks as if it were browned, not blued.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.