I shoot various surplus light ball through my M44 (I've shot Soviet, Czechoslovakian, Polish, and Bulgarian through it so far). I've also shot Wolf, Prvi, and Olympic through it in the past. POI and POA match quite well. Corrosive ammo does warrant same-day and more extensive cleaning.
My M39 does not like that stuff. POI is way above POA. At 300m I can aim for the dirt below the target and still have my rounds sail over the target or just hit the top support for it. At 150m I'm still hitting around the top of the paper when aiming at the bottom of the target or just below it. Sights are calibrated for the D166 round, which uses a heavier projectile with a different BC at a lower velocity. I recently tried Wolf Extra Match, which is Russian LVE match ammo. Uses a 200-grain projectile like the D166, but the specs aren't quite the same. At 300m rounds hit the top of the paper when aiming at the 6 o'clock position on the bullseye, but all shots fall on paper, and at 150m they're still hitting above the bullseye, but not by a whole lot.
Groups using LVE are tighter than any other ammo I've tried in either weapon so far. Some surplus light ball it should be noted shoots better than others. I've also had issues with the brass in the 1950s Bulgarian stuff, to include split cases and even a case rupture. Fortunately, the Mosin-Nagant diverted all of the gas away from me. It did have the bonus of coming loaded on chargers, however.