My experience with an older Ruger Mini 14 mirrored that of Furhunter exactally. I scoped mine and realized that this was by far the most inaccurate gun I have ever owned. Now this is from a big Ruger fan. Love my single action revolvers, Mk2 22 bull barrel, and my old tang safery Model 77 in 30-06. I still regret selling an old model 77 bull barrel in 243 as it was the most accurate production gun that I have ever owned.
When Bill Ruger was interviewed one time he stated that the Mini 14 was "An expensive plinker". Believe him. If you want to burn up a lot of ammo in a short time, the Mini 14 will do that. With the gun I had anything smaller than a cantalope at 100 yds was pretty safe.
So, with all that being said, I would not waste my time, money, or ammo on scoping a Mini 14.