Howdy
The big screw on the top of the top strap indicates it is a 3rd Model Russian. Here are a couple of photos of my 2nd Model Russian. Notice there is no big screw on the top strap.
If it is a copy, it is a very good copy, perhaps a Ludwig Lowe or a Tula.
Generally speaking, cheap European copies of S&W revolvers, especially those made in Belgium can be spotted a mile away. Here are a couple. Notice the trigger guards are crudely screwed on from underneath. S&W inletted the triggerguard into the frame and attached it with just one screw at the rear of the triggerguard, a much more subtle approach.
Some European copies even had the nerve to stamp Smith and Wesson, or other misleading information on them. It was difficult for S&W to enforce their patents and trademarks in a foreign country, although they did manage to shut down one Belgian operation.
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So here is what we know from your photos. It is a 3rd Model Russian. In addition to the big screw on top, the 3rd Model had a shorter extractor housing than the 2nd Model, and the front sight was forged integral with the barrel, rather than being a separate piece pinned to the barrel. If you look you can see the pin holding the front sight on my 2nd Model. From the angle of the photo I can't see if your front sight is pinned on or not, but it should be obvious when you look. To my eye, it looks like yours has the shorter extractor housing of the 3rd Model.
I'm pretty sure all the Russians S&W produced for the Russian government had Cyrillic markings on top of the barrel. My 2nd Model is a commercial model and is marked in English, as were all the S&W produced commercial models.
It's too bad all the markings have been polished off because that would have told us everything. What intrigues me is what looks like the remnants of an imperial acceptance mark still visible on the top rib just in front of the cylinder. It is difficult to tell, but it looks like the mark on both the S&W produced revolvers for the Russian government and the mark on the Ludwig Lowe revolvers produced in Germany. But it is very difficult to tell, so much of it has been polished away.
See if these links work. This one is for a 1st Model Russian. Not what you have, but the imperial acceptance mark is clearly illustrated.
http://www.smithandwessonforums.com/forum/s-w-revolvers-1857-1945/20281-second-issue-first-russian-contract.htmlThis link shows the markings on top of a Tula produced revolver.
http://www.smithandwessonforums.com/forum/s-w-revolvers-1857-1945/6538-3rd-model-russian-tula-contract.htmlHere is what The Standard Catalog of Smith and Wesson has to say about the Ludwig Lowe and Tula Arsenal copies.
Ludwig Lowe: Not made by S&W but a copy of the third model Russian made by the German firm of Ludwig Lowe for the Russian government. Cyrillic barrel markings will bring almost as much as S&W Cyrillic Russian contract gun. Commercial Ludwig Lowe revolvers with the markings in English are more scarce, and may bring a bit more. It has been reported that Ludwig Lowe copies marked with "RA" inside the letter Q on the rear of the barrel rib may have been revolvers made for the Argentine military. Values similar to S&W produced guns.
Russian Tula Arsenal copies: The Russian government also produced their own copies at their Tula arsenal, again cyrillic marked. Very rare in the US and reportedly quite scarce in Russian as well; 50% premium.
So, I cannot say for sure what you have there. It could be an original Russian produced by S&W for the Russian government. It could be a copy made in the Tula arsenal. It could probably be a Ludwig Lowe too because I believe all the Russian models accepted by the Russian government had that same imperial acceptance mark on them.
Not much help, huh?