As long as you are 922 compliant you can use any high cap mag made in USA.Surefire is expensive and that is why most people choose to convert their Sagas and put in a bullet guide. Use a USA made stock and pistol grip and fore-end with a USA made high cap mag and you are 922 compliant. I did all of this except the bullet guide and the gas piston and am still legal. This applies to any Saiga with a one piece receiver/trunion. If the trunion is separate you will need to do a total conversion. This is what makes the 223 so popular, no separate trunion.