"...this is common sence(sic)..." Not to mention that hunting with ball ammo is illegal in most places.
"...How accurate are these things?..." The Moisins we had in the shop I worked in long ago and long before there were any Stateside, were dead on at 200 yards with surplus ball and the issue sights. There was no hunting ammo available then. It was a reload thing entirely if you wanted to hunt with one.
Now, however, there is all kinds of U.S. factory ammo loaded with hunting bullets.
If you're short of money, putting on a peep sight will cost you more than the rifle is worth. Get some hunting ammo and go sight in. Wolf, for one, loads a 200 grain SP.