Ruger mags are proprietary and damn expensive Ruger mags are proprietary and damn expensiveThe Tapco Gen2 polymer mags aren't bad at all. Those are the ones with the steel reinforcing tab on the front, to prevent the plastic from wearing on the rifle's mag locating pin. Fit seems to vary based on series, though, but they're inexpensive enough to buy and try.
The Ram-Line AR-Mini combo mags were pretty good for range use, I used to have a bunch of those which worked perfectly in both rifles. Others hate on 'em, but I liked the little translucent devils.