In 1940 the Finn's tested Russian and Finnish ammo in a Finnish rifle ( they didn't say which one ).

Results -
With 5 shots at 100 metres:

the Soviet D-ball printed 83 mm

the Soviet L-ball 89 mm

the Soviet AP printed 128 mm

the Finnish D166 printed 19mm

I still have some WW-2 era Finnish ammo in the 15 rd pasteboard boxes squirreled away.

The Finish ammo companies Vihta Vouri  and Lapua make extremely high quality components and ammunition.

The Finnish people love shooting and they demand the best.

Russia's problem is that they have not valued the lives of Russians since 1917, and the average Russian conscript was and is little more than cannon fodder under Russian military doctrine - so the ammo doesn't need to be accurate in their view.

This is not to say Russians cannot make accurate arms/ammo.  Their Olympic guns/ammo are often excellent, as are their sniper weapons, and their designated-marksman rifle, the SVD (which is not a sniper rifle in the Western sense).

The only Finn ammo I have is 7.62x39 Lapua that SOG had years back.