Dona,
On the old Fido firearms special interest group, we had numerous insiders including a gent (whose name escapes me) who was the head of QA for years at Ruger. He took great pains to indicate that unlike the M-14 or M-1A, the mini-14 did not have parts tolerances that would permit routine MOA achievement through tweaking. Those that have, like Chief AJ, use numerous homebrewed custom replacement parts resulting in an overall cost that most do not feel justified in spending. What I would recommend to you is checking out Chief AJ and his price list...he guarantees MOA and in some cases better than MOA results and has practical demonstrations on that puppy's accuracy (saw him at the first varmint hunters' association jamboree in Pierre SD several years ago...his Ruger 10/22 was hitting amazing groups at 200+ yards too but at over $1500 it wasn't about to dent my checkbook!).
-=[Bob]=-