Please check the installation of your sizing die. If your sizing die is installed too deep in the press, this can cause the relationship of the primer arm to the Safety Prime trigger to be mismatched.
Screw the sizing in until it touches the shell holder, release the ram, and screw in another 1/4 turn.
Discovered March 25, 2024: on the small "S" trigger, there is raised flash on one ejector pin that wedges the primer shuttle open releasing the primer prematurely. Here is a video clip to showing the faulty operation: https://vimeo.com/927200311/1fadfeed6a?share=copy. The fix is to simply remove the flash on the offending ejector pin (see attached photo circled in purple). No need to disassemble, a quick swipe of an exacto knife will work.
