I still have only fired 51 rds from the .17 WSM B-mag. On my last range trip, I saved 7 cases for examination later. Finally got around to looking at them closely. Two of the seven had cracks. One was a minor split at the neck that I would not worry about at all. The 2nd was split from the neck clear down the case to about halfway to the rim. That was ugly. I did nothing to it. It is just as it looked after firing. I still consider my bbl to be in the break-in phase, but wanted to share this pic. Be sure to wear you eye protection lads.

Irish