Walter Dalrymple Maitland Bell killed several thousand elephants using the 6.5 Swedish or a 6.5 MS or 7mm Mauser.
The reason for his success was he used the heavy for caliber 160 grain fmj round nose parallel sided bullets which were common military ammo for the late 1800s. He used the same type 175 grain bullets in 7mm Mauser.
Those bullets penetrate better than any other type. Bell knew where to shoot them and those heavy bullets went right through them.
Why did he have to kill so many? Seems wasteful.
I found my copy of “Under a Lucky Star” by R.C.A. I misremembered. He took two shots on the running bear.
It turned out to be a big sow and two near grown “cubs”. He was walking along a “partly dry stream bed”, not the beach, and it was a log jam, not driftwood. It was likely sometime between 1910 and 1920.
In my copy it is on page 120.
In 1966 I killed an elephant in Vietnam with a single shot from an M-16.