Did Pam Ewing ever shoot JR?

No, Pam Ewing never shot J.R. Ewing in the television series "Dallas." The character who shot J.R. was Kristin Shepard, his mistress, in the famous cliffhanger ending of the 1979 season. Pam, J.R.'s sister-in-law, had a complicated relationship with him, but she was not involved in the shooting incident.