The US Navy sent Frank Marquardt to Germany after WWII to investigate aircraft machinegun development. He was interested in the revolver gun type weapon and on 7 Dec 45 made his first sketch of the Marquardt gun. The result was the Mark 11 Mod 0 20mm machine gun. I have attached a photo with some of the rounds for that development program. They are a very interesting variation of a rimless grooveless case that was held in a carrier that fed into the weapon.
From left to right: A brass case, electric primed case, headstamped FA * 49. The rotating band is flanged over the mouth of the case.;; The same round except there is no primer and the headstamp is FA 50.;; An early dummy variation loaded with a 1950 dated T114 Practice projectile. There is no primer pocket in the case, the base being flat and smooth. The headstamp is FA 50. A steel band is fit into the extractor groove. This is basically a modified T132 dummy round, which had an identical case to the Navy's 20x110mm Mark 100 series ammunition. The only difference is the reshaped shoulder and neck on the case.;; A scarce electric primed steel case version with a one piece steel projectile. Headstamp is EKCO 51 X.; Equally scarce aluminum case. Electric primed with the headstamp FA * 48*. The projectile is the M99 and is a mis-match for the case.;; One version of the aluminum carrier with a cartridge identical to the second round with the FA 50 headstamp. The primer pocket for the carrier is empty.;; Another carrier design with an electric primer.;; A third carrier design, electric primed with a link still attached. One of the most common links was simply a twisted wire, which I unfortunately do not have.
From left to right: A brass case, electric primed case, headstamped FA * 49. The rotating band is flanged over the mouth of the case.;; The same round except there is no primer and the headstamp is FA 50.;; An early dummy variation loaded with a 1950 dated T114 Practice projectile. There is no primer pocket in the case, the base being flat and smooth. The headstamp is FA 50. A steel band is fit into the extractor groove. This is basically a modified T132 dummy round, which had an identical case to the Navy's 20x110mm Mark 100 series ammunition. The only difference is the reshaped shoulder and neck on the case.;; A scarce electric primed steel case version with a one piece steel projectile. Headstamp is EKCO 51 X.; Equally scarce aluminum case. Electric primed with the headstamp FA * 48*. The projectile is the M99 and is a mis-match for the case.;; One version of the aluminum carrier with a cartridge identical to the second round with the FA 50 headstamp. The primer pocket for the carrier is empty.;; Another carrier design with an electric primer.;; A third carrier design, electric primed with a link still attached. One of the most common links was simply a twisted wire, which I unfortunately do not have.
