I think I might be the only person ever to have achieved this?
But then a 4 screw plate on a one-piece mount exerts a lot of pressure....even if there were only 2 bearing on the section of the receiver forward of the port. If it had been a cheap and nasty alloy it would have given before the action.....which would have saved the head and heartache... dunno me own strength sometimes. I now use a torque driver on everything.
Rumour hath it that Sportsmatch make the mounts for AI does it not?
Sportsmatch are hardly of the of the quality of your average 1960's Japanese motorcycle bolt.
Fizz