I went out on the last day of duck season last year and after all was said and done, I left six shotgun shells in my coat pocket. Since that day the coat hung on the rack inside the house until today.

When I got out of the jeep I felt the shells and figured I would use them first. None of them fit in my magazine tube. They were acting like I was sticking a 16 ga shell in a 20 ga pipe.

I set them aside and used some boxed ammo that fit with no issue. After I finished hunting I loaded them directly in the chamber and shot them off. No problems.

Anybody heard of shells swelling like that? They were Remingington Hypersonic 3" 20ga steel shot.

Some moisture may have got into the shells and the steel shot rusted causing them to swell. Shells like that where the shot has rusted into a rusted slug has been known to damage barrels. Or it could be rust between the metal base and plastic where the rusting has increased the diameter of the metal base. If so, you would risk a shell separation while shooting and leaving the plastic portion in the barrel. This would be a barrel obstruction for the next shot and likely damage the barrel also. I would not shoot any more of them if you still have any of them.

Thats why u need to use lead LOL

LOL. I think the GW might frown at that idea.