I love my Finn...it's the tiniest hair less accurate than my Swiss K.31, and almost as good as my buddies National Match 1903...MOA all day, probably sub- if I really put the effort into working up a dead-perfect load instead of my current 97%ers.
I've got a '42 Izhevsk 91/30 that'll throw 2.5inch groups at 100 yards all day with Czech silvertip ammo and the bayonet mounted. It's a total run-of-the-mill counter-bored refurb. But if I feed it anything else, the groups open up a BUNCH...It's nothing remarkable for accuracy, but they weren't INTENDED to be match rifles. Try some of each kind of surplus ammo, and find what works best for your particular rifle.
Slug the barrel, work up a good load for it, and watch your groups tighten up. Heck, just going from the cheap surplus ammo to good commercial stuff will do a lot.