Charles Robert Darwin.
Darwin's pistols were fairly low cost and may have been second hand - but they were anyway not 'London Made' - said to have been made by provincial gun maker Hanson of Doncaster.
This pair of side-hammer box-lock percussion single shot pistols, fitted with belt-hooks, were of 18-bore (.637") having six inch barrels - and were later given to Syms Covington, - Darwins manservant and assistant - at the conclusion of his service.
Syms Covington settled on the south coast of New South Wales some time after the end of the Beagle's Historic voyage - where he became the second Postmaster of Pambula, near Eden.
Quote from Charles Darwin:
"In the latter part of my school life I became passionately fond of shooting, and . How well I remember killing my first snipe, and my excitement was so great that I had much difficulty in reloading my gun from the trembling of my hands. This taste long continued and I became a very good shot."
Link to an article claiming that Darwin had an unhealthy obsession with killing animals:
In August 1863 during a spirited exchange of ideas with Joseph D Hooker, the prominent botanist at Kew Gardens, Darwin wrote:
"About New Zealand, at last I am coming round & admit it must have been connected with some Terra firma; but I will die rather than admit Australia."
The Media Of That Era Were Very Rude to Darwin.