Tungsten Ammo Shatter Failure Theory

[rexford]

The velocity versus angle curve for shatter failure of tungsten ammunition predicted failure cases for 17 pounder APDS where the round had more than sufficient penetration to defeat target armor, but failed.

Since the original posts, additional research using data from Thomas Jentz' Germany's Tiger Tanks, Tiger I and II: Combat Tactics, has indicated that 6 pdr APDS succeeded at velocities where the tungsten shatter theory predicted failures.

An additional contradictory case has been discovered with 90mm HVAP. The penetration curves following Page 17 in WW II BALLISTICS: Armor and Gunnery, by L. Bird and R. Livingston, were revised to depict the shatter failure velocity vs angle curve which appeared to apply to 17 pdr APDS. Two 90mm HVAP penetrations occur at velocities slightly above the shatter line, which theoretically would result in failures.

While 17 pounder APDS failures and successes for cases with overpenetration of the target are in complete agreement with the previous theory, 6 pdr APDS and 90mm HVAP firing tests are not consistent with the firing test data and theory.

So one can either assume that there is something about 17 pdr APDS that has it follow a firing test curve for shatter failure while other tungsten rounds do not, or one can take the approach that the 17 pdr APDS agreement with theory is a coincidence and the theory would be be disproved if more firing tests were made at velocities within the shatter fail zone.