My well-worn 1943 SKy M39 is one of my favorites - a very smooth 2 stage trigger on it.
People often call a mosin, a nagant, because technically they are mosin nagants. The Belgium gunmaker, Nagant, designed the feeding system on the Mosin Nagant whereas the Soviet gunmaker, Mosin, designed the rest of the rifle.
Collectors refer to the rifle as Mosin and refer to the 1895 revolver as Nagant. It does get confusing to see a posting using the term Nagant and then see that the posting is about a rifle. It happens so commonly that I have gotten used to it and deal with it accordingly.
The fact that most dealers don't know the difference between Finns and Soviets and other details about these rifles has enabled me to get some very collectible rifles at dirt cheap prices. The internet has made these deals occur less often and dealers generally now know the difference.
So, if you want to appear to be a knowledgable collector, don't call a Mosin a Nagant.