***Princip fired his Browning 9mm pistol***
Browning .32 auto pistol. I used to have one just like it.
In the book “John Browning, American Gunmaker” It mentions that one of his FN .32 autos was used in the assassination. No one remembers his commenting on that fact.
Interestingly, the little .32 was his favorite pistol despite the fact that he designed some of the most famous pistols ever.