I had the Ranch model of the Mini-14, the one that came with mounts for the scope rings that they provided. I never could get that gun to stay consistent, and at some point during every single range trip the Ruger provided mounts would loosen up.
The best day I ever had shooting with that rifle was the day I took the scope off and used the stock sights. I didn't even adjust them, I just popped up the back sight and put a mag through it at 50 yards.
Please post if you have better luck with your optic setup than I did. That always kinda bugged me about the rifle, almost as if it didn't want you to try to make it too serious/accurate.
H&K Weapons -
9mm P7 PSP
.45 HK45 w/ Streamlight TLR-1
.45 USC/UMP Conversion w/ Eotech 512
Under Construction -
POF P-415 (AR15), Gen 3 Lower, Magpul UBR Stock, Enidine Hydraulic Buffer, Trijicon ACOG (model unchosen)
Everything Else -
.22 Browning Buckmark, Threaded Barrel, Barska Dot Optic
.22 Ruger 10/22, Threaded Barrel, Leupold Rifleman Optic
.22 AAC Pilot Suppressor (attaches to both above)
.22 Marlin Bolt-Action
.20-gauge Browning Pump