Seeing it’s jamming consistently on the third shot, try only loading 6- 7 rounds instead of 10. There may be an issue with the inner magazine tube, (ding, dent) which is slowing or restricting the 3rd round from feeding smoothly. You can check by pushing shells into the tube and see if you run into any resistance as you are hand feeding them singly up the tube. If the tube doesn’t have any problems the spring inside may be weak from being left loaded for an extended period of time.

Erin