Buy a K-31. You won’t regret it. They are worth far more than their price on the current US gun market. I bought one for $225 at the Tucson gun show last winter. I took it out to the range and fired three shots at 100 yards from a sandbag on a bench. The group was like a small three leaf clover right on the edge of the ring dividing the center target X from the 10 ring. Iron sights and my crappy middle aged eyes only. The old beechwood stock looks like hell but the damn thing shoots like a match rifle.
I bought a K-31 about six months ago. First time I shot at the range I had the strange sensation that I had a scope mounted on the rifle... had about same group as you.
Did your rifle have the previous owner’s name under the butt plate?