Take the barrels off, push ejectors down all the way if they do not work freely. Load a new shell in each barrel and see if they stand up slightly above the face of the barrels. If they do then rims need recuttig. A shell fired in another gun swells usually and i have found that sometimes they will not fit properly in another guns chamber.Also check to see if any trash or? is under back of ejectors not allowing them to seat fully. SkB can fix you up! Bobby