I don't know about the SKS but the Mini-14 can be tinkered with to get around 1.5-1moa. Sub moa is rather difficult, but it's possible. The newer ones (580 and 581 series) are often 2moa out of the box.
This forum has a lot of information on how to do so:
http://perfectunion.com/vb/forumdisplay.php?f=106