by critical mass » 20 May 2021 14:39
Too many assumptions.
(A) there were VERY FEW normal obliquity tests against the T44. Altough shot by shot data are missing, only four out of fourteen tests were within the proof angle of either 75mm or 88mm Pzgr.39. Thus, the majority of the penetrations should behave exactly as observed. Further, only ONE shell can be charackterized as undamaged in the photo. All shell hits on the front were > proof angle for the Pzgr.39 and the majority of side hits were also at resolved netto compund obliquity >45 deg. The only tests against the side at 30° or 0° yielded such low PSP velocities (487m/s and 595-596m/s) that no damage would have occurred at all to any 88mm or 75mm shell. Without knowing which projectile corresponds to which test, assumptions are uninformed, and thus, not a good advisor. Because they fired life shells, all functioning shells would be highly fragmentated. You wouldn´t have them selected for the photo. This can bias Your perception considerably.
-Also, impacts at high obliquity do render the projectile defunct primarely by forms of base slap, which damages the fuze adaptor. Nose breakage against high obliquity targets is a good feature as it inhibits ricochet.
(B) the 2nd image shows an early KW armor trial, at which time the 5cm Pzgr Gg were in service, primarely. These early ww2 uncapped 5cm shells started to experience break up at ca. 600m/s terminal velocity against a target plate, which they could barely perforate. Those shells would break up against a discriminate target, such as those 75mm plates depicted. Again, You are assuming the projectile was intact, but the fact that the nose is not shown tells me that this is not a likely assumption. In low obliquity impacts the function of a shell is compromised primarely by nose breakage or compression reaching down to the cavity. These shells could not be relied upon to survive this impact in a condition fit to burst.