In the meantime ...

... a fairly good account of some of Selous' rifles was made at, of all places, Bonham's auction house ...

I must've looked at that page half-a-dozen times, but always in regards to his .256, then up for auction, never taking the time to read the entire description ...

... "Selous used a variety of guns throughout his hunting career. He landed in Africa with a .577 (Snider) double rifle by E.M. Reilly, but this was stolen whilst on his way to Matabeleland in 1871, and was replaced by a pair of Hollis 4-bore muzzle-loaders. These were joined by a third, a converted duck-gun, which he bought from the South African hunter Jan Viljoen and which was to remain with him for the rest of his life. He also appears to have obtained another .577 Snider rifle as a replacement for his stolen Reilly, although he seem to have preferred the 4-bores. On his first trip back to England in 1876 he bought three new rifles, all single-barrelled breech-loading rifles of large bore. These were all superseded four years later by his .461 Gibbs-Farquharson rifle, which was to be his standard rifle until 1895 when he tried his first "small-bore" rifle, a .303 Lee-Metford loaned to him by Henry Holland after his Gibbs went missing. Between 1896 and 1915 he tried a variety of calibres, including .256, eventually conceding to his biographer, J.G. Millais, that he would have been better off sticking with two calibres; one such as the .256 Mannlicher for small game, and a .450 Rigby or equivalent for heavy or dangerous game." ...

https://www.bonhams.com/auctions/17947/lot/298/

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