Well, the rifles were made by several different companies. Get the model number from your rifle, and go over to gunpartscorp.com website. Scroll all the way to the bottom of home page, and you will see "cross reference". Click that, and scroll down until you come to your rifle- and it will tell you who made it, and what the original model was. Then go to that make and model on their website, and see if they have a magazine for you.
What we have here is... failure- to communicate.