The discussion of acceptable accuracy and function of a Mini 30 is pretty broad in spectrum. Some folks love 'em, and some folks not so much. I have been well pleased with all of my Mini's, both in .223 and 7.62x39.
Part of the attraction of the Mini 30 is the capability to use really cheap steel-cased commie bloc ammo. I'm not here to profess the acceptability, or not, of this cheap ammo, but it's a fact of life that many folks are using it. My interest in this cheap ammo is it may well be the only stuff available at one time or another.
Another option, at the other end of the spectrum, is domestic ammo. Very expensive. At nearly a dollar per round for ball ammo, it kind've negates what these guns are all about.
A middle-ground choice, is Eastern European brass-cased ammo. I have bought, and experimented with both PPU and Sellier and Bellot ammo. My experience is this is very high quality ammo, for far less cost than domestic ammo. I've found PPU available on-line for less than 10 bucks per twenty rounds, and just yesterday I found S&B packaged in a (Cabelas) Herters brand box, for $10.19 per box of twenty. And these are both soft points.
This imported brass-cased stuff functions perfectly, and my experience using iron sights is it just as accurate as any .30-30 I've ever shot. I've never scoped a Mini 30, and maybe if I did I'd discover unimpressive 3-inch groups. But again, I don't consider this little gun to be a target gun. It's a gun that I can have in the back seat, put it in service quickly, and expect to hit anything I can see with iron sights.
WAYNO.