"Welin" . . . "''Welin Breech''" . . . . "Vickers design" . . "Welin breech block" . . "Welin-type breech" . "Welin breech block" . "Welin-type" . "Welin screw" . "Welin interrupted-screw breech" . "Welin type" . "Welin interrupted screw breeches" . "Welin interrupted screw" . "Welin breechblock" . . "Welin breech" .