carrying a rotably mounted obturating plug of the screw-thread or the interrupted-thread type (F41A3/30 takes precedence)

Full Title

Breech mechanisms, e.g. locks > Block action, i.e. the main breech opening movement being transverse to the barrel axis > with pivoting breech-block > carrying a rotably mounted obturating plug of the screw-thread or the interrupted-thread type (F41A3/30 takes precedence)