What does "SA" mean on a Mosin Nagant rifle?

Answer 1

"SA" is a property mark for the Finnish Army and stands for "Suomen Armeija".

Answer 2

Above answer is right on.

Finn Mosins were generally heavily modified from the way the Russians built them....and that's very desirable from both a collector's and a shooter's point of view.

These were captured rifles that the Finns put heavier more accurate barrels, sights and stocks on. They were also well 'tuned' by Finn armourers.

As there are not as many, they are also less common. Expect values to be three to five times that of a Russian Mosin, which now sell for about $90.