Remington Model 870 1

I purchased the 870 Supermag last year during the middle of duck season. It jammed often. I figured I just need to get more comfortable with it. Now it is already the second week of duck season, I have gone out twice and I am still having the same problem. Can anyone help me? Any advice out there? I am not made of money so I don't think I can pick up a another shotgun before the end of duck season.

I owned a Winchester 1300 Defender (not for duck hunting), and it never once jammed on me. In fact, the recoil assisted the cycling of the pump action which made for quicker follow-up shots because it pushed the pump rearward. To complete the cycle all you had to do is push the pump forward and you were ready to pull the trigger.