A U S Navy ships surgeon wrote an article on injuries due to AD of 1911 pistols during his service in WW2.
He'd treated about sixty such injuries, and almost all were due to insufficent training of younger officers.
Another factor was loosely fitting replacement parts of pistols hurriedly refurbished to fill the need for sidearms.
Similar problems were encountered during the Vietnam era.
a police department in one of the Northern states had an unacceptably high number of AD while using a double action S&W revolver.
They called in all these revolvers and had the single action notches ground away, making these DAO. After that they had very few if any AD so long as these revolvers were in service.