Well, i reckon its the silver riser part (if that makes sense) The balls just keep feeding and it means there can be arround six balls in the breech at any one time instead of one
I have an old bone daddy gl, the detent on that is very obvious - being a small 'ball spring' screwed into the side
I'm not sure which detent the gl uses, there should be something just forward of the ball in the breach holding it enough until the bolt goes forward
If its a spyder detent thats needed I may have one in one of the various spares bins I have! Post a pic of what uour one looks like and I will try to match it (or near as damn it)