My experience with these rifles is not great, but all is not well with that bolt. It looks from here that the stud of the cocking piece (or something else....) has damaged the safety stud of your bolt. That is the stud to the rear of the short and long cam groove. It shows signs of extensive damage and burring on the face that faces the short/long cam groove

Is this damage what you refer to as 'the horseshoe' shaped lug'?