Actually, the pin which falls out when the toggle is removed from the receiver and turned sideways is the short one which connects the breechblock to the middle link. The pin cannot, under normal operation, fall out; as it is partially blocked by the sides of the receiver. At least . . . that's my opinion. Just wondered if I was overlooking something. Mechanical failure of the toggle during firing seems hazardous.
I agree, if that rear receiver axle falls out during firing the shooter is in BIG trouble.
Luke