Originally Posted by
NutLoose
......As for a shouldered bolt, there might have been good reasons, such as the reduced diameter threaded portion if the bolt was shouldered not being of sufficient strength so as to not fail in the case of an ejection, and the main shank of the bolt not having sufficient clearance in the shackle for its diameter to be increased.
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Nope. the shouldered bolt design had been in use for decades. My first encounter was in 1963 on JP Mk4 seats. Their use continued at least to Mk 9. Ejection forces would have negligible (if any) effect on the bolt which only serves to hold the drogues (same sizes) attached until the aircrew/seat separate.