Mdt makes a great magazine - MDT Metal AICS SA 12 Round Rifle Magazine

Fits a lot better than the Magpul mag that my 6.5 CM Savage desert tactical shipped with. Locks up solid with very little play. A little rough at first, but after a few rounds fed and cycled smoothly, which was expected. Feels very solid and well built. If you want a mag that doesn't flop around, and works as it should, it would be hard to find a better one, especially for the price.