Kerryman, my good man, a book I do have in my grimy mitts, I finally won an auction, was written by R Gordon Cumming, who went to Africa with a Dickson two groove, a James Purdey and a William Moore in 1847.
Regrettably both the William Moore and the John Dickson blew up after months of hard use. He had to finish up his work using his Purdey, even though the Purdey was used as hard or even harder than the other two, as he puts it "a faithful friend that has saved my life on many occasions from charging brutes"!!!
Let the others talk of shooting a bunch of stupid glass balls and clay targets!!!