Mauser BK-27

Design

The Mauser BK 27 is a single-barrel, high-performance cannon that uses a breech-cylinder action. It is fully automatic, electrically fired, and gas-operated, with a selectable rate of fire of either 1000 or 1700 rounds per minute, plus or minus 100. The weapon cycles using pyrotechnic cocking charges. It is mounted on the Panavia Tornado, the Alpha Jet, the JAS 39 Gripen, and the Eurofighter Typhoon.

Lockheed Martin once looked into producing a licensed version for the F-35 Lightning II. Rheinmetall has created remote-controlled naval variants, the MN 27 GS and the MLG 27, which are fully automatic naval guns. The German Navy has ordered ninety-nine MLG 27s. The cannon primarily fires mine shells, which are considered most effective against aircraft, and also uses armor-piercing rounds such as the frangible armor-piercing shell designated Fap 27 mm x 145 mm ammunition/peb327 (DM103).

In his book Typhoon, former RAF pilot Mike Sutton described an incident during a strafing run in Syria in support of Allied ground forces against ISIS. He reported that his 27 mm cannon jammed after firing twenty-six rounds, with the heads-up display showing "GUN FAIL." During the debrief, it became clear that both pilots and ground crews were aware of this problem. One pilot told Sutton that the issue had supposedly been fixed, to which Sutton replied, "Exactly. We've been here before."