As I have always said - crappy ammo is one or two of the MOA on any AK.
Go get some Federal Powershock SP's and shoot that. You'll see. $20 for 20.
I assume the Corbon is more like $50 for 20. But you should treat yourself once just to know it's not the ammo (which leaves you or the gun).
You gotta get out of the cheap rocks attitude. An $800 Bulgarian/Saiga with that corbon is a TOTALLY different creature than a Romy with Bear.
And yes - I find the Corbon VERY prohibitive for every day (or even every month use). But for occasions where accuracy counts (like a hunt, or an SD ready mag)...hard to argue.