Either Invector or Invector+ depending on how it left the factory.
Best left to a trained gunsmith.
Use the Owners manual for safe cleaning and breakdown instructions. They are available at the Browning link below and it is free.
Choke size varies. You will have to take it to a gunsmith.
take it to a gunsmith
Look at the choke tubes.
Should have choke tubes, being that you can change it to whatever choke you want, so there would be no marking on the gun. There would be markings on the end of the choke tube though, usually between 1-5 lines. Not positive on which means what, but I believe the higher the number the tighter the pattern. But take that with a grain of salt.
Out of What
how to change choke cable
50-500 USD give or take.
You may have a broken extractor.broken ejector of both on your rifle.I would surely take your rifle to a qualified gunsmith to identify and fix the problem.
Download a manual from Browning or take it to a gunsmith
You will need to call Browning or take it to a gunsmith.