Long-time readers of this blog are no doubt already aware of the poor performance of German armour in British and Soviet trials, but you can never have too much evidence. Here's another log for the fire.
"(a) 17 Pr v Glacis
Gun performance is appreciably better than forecast and it must be therefore be concluded that German plate is not up to the standard of our Homogeneous M.Q. tank armour.
In point of fact the German plate appears far too brittle and large cracks develop from any penetration. These became so bad during the course of the trial that whole sections fell away and it was difficult to find a target in the later stages.
This fault is not confined to this particular plate as the tank used as a target had been knocked out by penetration of the turret side, by 75 mm AP, and from here the cracks had developed to the side of the plate."
Mediterranean Area A.F.V. Technical Report No. 23 - Part II Enemy Equipment - Panther
14th September 1944