The problem was with the hotspot, it should be placed in the center of the object. This solved the issue with the shotgun shell
However it doesn't solve the shotgun issue. That's because of the shape of the shotgun. You might have to use an invisible rectangular object to apply the physics to and then align the shotgun to it
The collision Shape of the shotgun under advanced in the physics options was not set to Box - so I changed it, (I noticed that the shotgun Shell had it selected). By tweaking the hotspot it now works without the need for an extra invisible object
thanks for the help but still a's backdrop works better.
This is strange. Sorry that fusion 2.5 is impossible to adjust the collision
Question did you try using physics ground object?
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