method of operation. This used a 20×70mmRB cartridge and had a cyclic rateoffire of 300 rpm. It was used on a limited scale as an aircraft gun on Luftstreitkräfte
showed the potential of the single-barrel revolver cannon, the practical rateoffire of such a design was still limited by ammunition feed and barrel wear
was built in 1922. The base ring mount, which improved the effective rateoffire, entered service on USS Porter, commissioned in 1936. Among naval historians