My wife has owned her 3913 for 30 years. She bought it used, but it has been absolutely reliable until recently. A few weeks ago, while shooting my reloads, she had several failure to feed issues. The rounds hung up partially into the chamber. This happened with more than one magazine. I suspected that that batch of reloads had some variation in physical dimensions. After that, I thoroughly cleaned the gun. Yesterday, she was shooting Winchester white box and experienced the same thing. I am considering replacing the recoil spring with a new standard power spring in case the original spring is suffering fatigue. I would appreciate any insights people may have. Thanks in advance.