I used to say use the promag 223 mag, but that was with the norinco 223 and the ak47 223 that I built. They wouldn't work for shioote in the 74. I tried tapco galil mags but after thinning them they would move up and down in the front and back so much that the bolt would ride over the rim. Just by chance I found the tapco m85 in my closet. I had forgotten I had it. Its identical to the tapco galil except that the tabs are thicker. After thinning it she clicked right in with no play, and the feed angle is perfect, and they have the nice no tilt follower design. Durability? Meh, but for a range mag +1.