Depending on the action mark...

There should be a short screw protruding through the LHS of the action, which acts as the kicker to toss out the fired case. The outer left side of the rim should hit against it a half-inch or so before the bolt is fully rearward, and stop. This is what throws the case out. Often they become worn or burred over and produce the result you are experiencing.

This may not be it, but worth checking before going further. Remedy is to replace the screw.