The little butterfly hammer block is not moving far enough out of the way. Probable couses are, The locking lugs are not engaging deep enough to push it out of the way, Your reloads are too tight in the chamber and not letting the action close all the way( which will also cause the lugs not to engage far enough ). From personal experience it's usually reloaded ammo that was neck sized only and the shoulder is not pushed back far enough to allow the action to close all the way. Hope this helps, KN
