The Leopard 2 uses composite armor, which is made up of steel plates, kevlar pads, ceramic plates, and open space, all designed to stop an incoming round. The Soviet 122mm m1931/37, the gun for the IS-2 and 3 tanks, using the same ammunition and at the same range, would penetrate ~125mm of armor.

To pull some numbers, the German 8.8 cm KwK 36, firing APCBC (Armor Piercing round, filled with explosives, designed to penetrate armor) would, at 500meters, penetrate an average of 110mm of steel armor. Even the big guns of the war, like the 8.8cm or the Soviet 122mm would struggle against a modern tank round.

Hence, 'doorknocker'.Īgainst a modern tank, the Pak36 would be completely useless. The round would make a loud BANG, alerting the tank crew to danger, and the flash would expose the guns position. So, the German 3.7cm Pak 36 AT gun was called the 'doorknocker', because except at close range, and against the vulnerable side and rear of a tank, the gun simply wouldnt penetrate. Previous AMAs | Previous Roundtables Featuresįeature posts are posted weekly. May 25th | Panel AMA with /r/AskBibleScholars Please Subscribe to our Google Calendar for Upcoming AMAs and Events To nominate someone else as a Quality Contributor, message the mods. Our flaired users have detailed knowledge of their historical specialty and a proven record of excellent contributions to /r/AskHistorians. Please Read and Understand the Rules Before Contributing. Report Comments That Break Reddiquette or the Subreddit Rules. Serious On-Topic Comments Only: No Jokes, Anecdotes, Clutter, or other Digressions. Provide Primary and Secondary Sources If Asked. Write Original, In-Depth and Comprehensive Answers, Using Good Historical Practices. Questions should be clear and specific in what they ask, and should be able to get detailed answers from historians whose expertise is likely to be in particular times and places. Nothing Less Than 20 Years Old, and Don't Soapbox. Be Nice: No Racism, Bigotry, or Offensive Behavior.

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Modern day anti tank guns