I've shot about 300 rounds so far through my new OSS since I got it a few days ago on the 10th. This morning, I shot a couple of 25yd groups for accuracy. I did a 4" group, standing unsupported, and a 1.75" group in a kneeling position with my forearms and magazine base resting on the bench. I hope it's repeatable, but things are looking promising!
This was with some Russian steel-cased 115gr ammo. I think it was TulAmmo or brown Bear, but I don't know for sure since I bought it last year and sealed it up in bottles without the boxes.