It's a long infantry m/91-there was little difference in length between the Dragoon and the m91/30 as the latter was effectively a modernized version of the Dragoon-Sestroryetsk ceased making the MN in 1918.
It's a wasted trip baby. Nobody said nothing about locking horns with no Tigers.
I'm Spartacus, not really i'm Paul!...
'SA' is the Finnish Army property mark-means it was owned by them after being used by the Russians-Finland had been part of the Russian empire prior to 1918-they inherited some rifles and bought others that had been captured during WW1-many were rebuilt into later model Finnish rifles (m/27, m/28, m/39 and m/91-see below example using a Sestroryetsk 1917 receiver).
For a good, online reference for Finish Mosin-Nagants and their accoutrements, see:
The Finnish Area