Ted will probably change his production dates when he sees this receiver. Lapin has too many mistakes to be reliable for anything, and he hasn't corrected them in his later editions.
When you physically see a rifle that changes the production date range, you have to accept it over some one's opinion. A good example is the Nagant revolver, production didn't start until 1899 according to almost every sounce. How do you explain the 1898 dated cutaway in the Tula Museum and examples of deactivated revolvers in Russia with 1898 dates and serial numbers in the 14XXX range?
If the rifle was from the range of 1910 to 18 it would have a 910 to 918 tang date and the arrow would be offset to the side, not centered.
I'm just tired of people quoting sources that defy what is in front of our eyes. Ted, at least has always been willing to update the data on his site. He still has some errors, but they don't seem to be permanent like your other source. I believe that it is a Sestroretsk 1891. I've always wondered why that factory would lag behind the others.
Im sure that you all know that any sestroryetsk arrow and date that are pre 1900 only have two digits seperated by the arrwow and any dated post 1900 have 3 digits with the arrow seperating the first digit from the last two digits. Like I said, im sure almost everyone already knows this but I just wanted to clear up any misunderstanding or such things when it comes to determining the year on the rifle.
I agree with everyone who said that an 1891 receiver is an awesome find. I have a Sestroryetsk receiver dated 1905 (I think) on a Finnish M91 (has 9 vertical arrow 0 5) on the receiver tang (what does the 9 mean anyway ?).