Thanks grouseman and drover - appreciate your suggestions. A while back I put the message on Rimfire Central - good folks there - they mainly pointed me to some available bolts, but all were for the next one or two models of that 46 and will not fit the original design. They also suggested Havlin - seems to be the main source for Mossberg .22 stuff - but already had talked with them and they said "no bolt available".
Am thinking the "will not open/cock" issue has to do either with some problem with the internal spring or with the current slope of the bolt twist facing, which may be worn. That face seems soft compared to the hard pin that rides on it.
Have taken the entire bolt assembly apart more than once (a bit tricky) and cannot find an issue with that spring - so? Am about ready to try "building up" that softer cocking slope a bit to change the angle of engagement. Any thoughts?
