I have a Mossberg & Sons Model 151M-Bthat was my grandfathers. I have always had trouble with it jamming. I think it may have something to do with the fact that it is fed through the stock. Does anybody have any suggestions on why it jams. Does the spring in the tube that runs through the stock need to be replaced? Is it a feed ramp issue? I would rather fix it myself if it will be easy rather than take it to a gunsmith. Especially if not much can bedone and it is the nature of that model.