However, based on no issues being found with the firing pin the only other possible issue that would prevent the firing pin from contacting the primer would be due to the slide not being fully closed. When this occurs it is usually from larger than standard ogive ammunition, or cases being slightly too long for this C.I.P.(European standard) dimensioned chamber.
Show me the data. Forgive me, but I think this is an assumption on your part, possibly based on your own experience. It's valid experience, but it's simply not the whole view.
The most likely reason for the chamber to be held open
in my experience is improper Taper Crimp. The there are several case abnormalities, including using cases that were loaded for Major PF rounds. Then there is also OAL simply too long. When you have a bullet like the Hornady XTP, the full diameter shoulder can stop the bullet from entering the chamber. The ogive is not in play at all.
Here's fired brass that won't/can't enter the chamber. No bullet is present.Then there would also be the situation where a 380Auto case slipped in and got loaded. If it were not held by the extractor, then the cartridge could fall about 1/10" deeper into the chamber where the firing pin could not ever make contact.
The number of possibilities for "screw ups" is endless.
And again, there is no one formula for the shape of an FMJ ogive.