For what its worth Wolf ammo shot groups almost twice as big as Monarch ammo from Academy Sports. Nothing shoots better than my handloads from my mini. And I didn't spend any time at all working up my load. Just made consistant ammo with each powder charge weighed by hand and even crimps.
Try a couple of boxes of good ammo from an american maker that is NOT bulk plinking ammo before you do anything to your gun. And clean the barrel with some Barns CR-10 too. And don't expect top notch accuracy till you have fired a couple hundred rounds and smoothed out the barrel a little.
And forget charts. They are normally based on 24" barrels. Do your own testing. Its the only way to know for sure how your rifle shoots.