The shell stuck in the armor and did not pass through the armor to detonate inside the tank. By German, Soviet 80% certified, and even US Naval penetration standards there was no penetration. See page on Penetration Criteria:
http://www.panzer-war.com/page33.html

Under these standards the GERMAN ARMOR WON! Now, it was cracked and broken so it’s freshness date has expired. The next hit on it will go through.

Another question on the 45mm gun fail. Why does the 45mm column on the Penetration table show that the 45mm will penetrate 24mm@30° at 1500m and (if we prorate) between 30mm-35mm@ 0° at 1500m?
http://tankarchives.blogspot.com/2013/03/penetration.html

Then why when tested at 1500m on the 30mm of ‘currently used by Red Army’ Izhor factory armor did it fail to penetrate? Was substandard armor used in the Penetration table tests or, were the numbers wrong in the Penetration table? Something is amiss here.

Where does the blame lie? In the Ministry of Armaments or the Ministry of Armor?

The tests showed that 75mm gun can pass through up to 70mm of spaced Armour at 30 degree incline.

Which in turn, left the US army overconfident in its AP capabilities

Quoting questionable source materials of mostly isolated cases and facilitated results does not help in this regard. The soviet test of the PzIII and IV plates alone is ridiculous as it is, contradicting actual battle experience in almost every possible way. Same with the long-time infamous “Firing Range” Test of the King Tiger, where they basically totally mutilated the thing from close range with all they had, gloating “hey look! we can bring it down just fine!” afterwards. Again: No shit, buddy.

In general: there is a good reason why most materials available on the western “allied” market leave out soviet reports and testing documents alltogether. Read some books about the Tiger as an example, paying attention especially to statements of veterans from both sides of the trench, which again easily devalue whole paragraphs of your article.

There should even be still something up on the wargaming.net site regarding the Market Garden operation, also involving firing tests by a firefly on a captured panther, where it took three shots at approx. 100 meters to penetrate (and subsequently shatter) the frontal plate.

Et cetera. In summary, and to keep this still relatively compact: This whole “glorious russian awareness offensive” you and a few of your friends are conducting is getting old – fast. Fielding “mythical krupp steel” shenanigans as a reason to spit out, in its absurdness very much comparable, “contra-propaganda” is a serious sign of… in lack of a better term… “butthurt”, and does not help your credibility as a semi-professional expert one bit.