Try Survivor's SKS Boards.
The Tapco 20 rounders are widely considered to be the only aftermarket mags of any capacity that function well. Any others are considered hit and miss at best, but someone there might be able to point you toward some. You will also see many stories from people who pulled out the integral mag only to put it back in after repeated reliability problems with detachable/aftermarket.
The United States of America: 1776-2012. You will be missed, but not forgotten.
Last edited by wavetrain75; 03-21-2012 at 22:07..