Quote Originally Posted by evert View Post
The HW bolt measures 7mm, the BSA bolts are 6,35mm/.25". So the holes have to be reamed for the HW bolt.
The HW bolt need extra fine threads cut into one side of the breech jaws.
The Mercury bolt just needs recesses, definately less work.
Dunno what diameter the hinge pins are but having tried for fit an old .22 mercury barrel on my 635 magnum I can say for sure the breech block hole is too large for the BSA bolt without sleeving the bolt.