I think there is some confusion on how to load a primer on the bare primer conversion. The primer needs to slide into the groove on the bolt. Not drop into the bolt like the Lehigh conversion.
The picture below shows the groove the primer needs to slide into.
The next picture here shows the primer in the slot on the bolt. The bolt will not close unless the primer is in the slot. And also the slot lines up the primer to go into the breech plug. It's really easy to drop a primer in front of the slot which will allow the bolt not to close.