Stay away with ProMag. They aren't called UN Mags for no reason.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Myself and the gun testing authors at Swat Magazine agree that the 30-round RAMLINE universal aftermarket mags function great and fit both the Mini14 and AR15 rifles.
Here's the SWAT Magazine article:
http://www.scribd.com/doc/46573196/200203-AR-15-vs-Mini-14
BTW, the MGW 90 round snail drum works great with the Mini14, I once shot so many rounds thru one of my Minis in one sitting using these drums that my barrel was nearly translucent orange.. LOL