The 20mm Oerlikon is a Swiss designed auto cannon used for high angle close range anti-aircraft fire, with an effective rang of 1,00 to 1,200 yards (915 – 1100m). The breech is not locked at the time of discharge and the round is fired a fraction of an inch before it is fully home in the chamber, the neck of the case swelling to form a gas seal. Muzzle velocity 2,725 ft/sec (830m/s) with a rate of fire 465 to 480 rounds per minute. The 20mm rounds are loaded into magazines holding 60 rounds. The last 2 rounds loaded are usually practice rounds so that if there is insufficient time to remove the muzzle cap the non-explosive rounds can blast through the cap.
The Mark II gun was made in Britain and in the USA principally for naval use. This animation shows the British Mark II. Models made in the USA are marked Mark II U.S.N or Mark IV U.S.N. There is no difference between these Marks and all three are interchangeable.
The animation was made using Cinema 4D and the music is ‘Song of Mirrors’ by Unicorn Heads. Source material: BR 274/41, OP911 and OP909 and author’s photographs.
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Hi, I’m Rob, otherwise known as VBBSMYT.
I create the animations on my iMac using Cinema 4D, which I find very intuitive, and allows me to add smoke and flames, and then send the model to my trusty Render farm.
I make my models as accurate as possible through reference books and particularly good drawings. You may have seen my animations of early torpedoes and machine guns on YouTube. I enjoy finding out how things work and it has been fascinating to track the development from the late Victorian period up to World War 1.