I have a Browning Sliver Hunter that I have had for 2 years. I have shot approx 1000 shells through it dove hunting and shooting skeet. A week ago the gun developed a tendency not to load the second shell in the magazine. It will hang up on the feed ramp and require manual extraction. The gun has been taken care of and cleaned regularly. I completely broke it down and cleaned it again and still the same problem. Interestingly if only two shells are loaded it will cycle both but will not cycle a third. This happens about 70 percent of the time. I have tried two types of ammo (winchester and remington) both cheap but never had a problem with it before. I really can't see any visable crud or damage. Any ideas?