I sure hear you on the Mini-14. I wanted that rifle to shoot well, it was just so damn nifty handling. Your grouping sounds like what I got, So poor it was impossible to adjust the scope to bring the “group” into alignment.
Yes, it really is a shame that a rifle which looks, feels and handles so well could not seem to be made accurate.
Ruger must have tried to correct the accuracy problem. It must have been endemic to the design. I recall reading many years ago that the British eventually gave up on making the Jungle Carbine shoot well.
They finally decided it was just part of the design.