External firing gear for guns using loose ammunition. The primer is
inserted in the firing gear when the breech mechanism is open, but is
held at an angle to the lighting vent until the final locking motion of
the breech block, making it impossible to light the gun’s charge before
the breech mechanism is safely closed, even if the primer should be
prematurely exploded. The primer case is automatically ejected by the
opening of the breech mechanism.