I went on a bushpig hunt and we were busy checking the rifles' point of aim when the back sight of the 500 Jeffery's barrel came off. These things are not supposed to happen, but my biggest concern is that it seems that the sight was merely glued to the rifle although there is a hole, but without any threading.Anybody with similar experiences?

Blaser ? Contact Mr Biebs immediately !!

There are many examples of high recoil guns needing extra strength . Cross bolts, larger scope mount screws etc, etc !
No excuse !

Sorry to hear about your rifle. My CZ 550 in 500 Jeffery may seem a bit brutish (on the heavy side), but as Boris the Blade said in the movie Snatch "heavy is good, heavy is reliable, if it doesn't work you can always hit them with it"

I'm sure that if you were to talk to the Krauts over at Blaser they would be more than happy to explain how their design is perfect. That you are too simple minded and ignorant to be able to operate a Blaser correctly. Yaah.....