An old .303 Cartridge

Yes, must be a Mk I Black Powder, Boxer primed, 215 grain cupronickel bullet (though doesn’t look it). 

You could never replicate the load due to the way it was manufactured, i.e. a compressed pellet of black powder dropped into an un-necked case which was necked prior to having a bullet pressed into it.

Where did you find it?

Found it in a conglomeration of old .303 cartridges that I bought some time back. Only sorted it out quite recently. Obviously, its previous owner was unaware of its significance. Initially, I thought it was just a Mk II or VI which I was weeding out to avoid having to shoot. I know absolutely nothing of its earlier history, but guess that it could have arrived in South Africa during the Boer War, which era cartridges are still not particularly uncommon. 

I mentioned this thread today at my weekly clay pigeon shoot when a friend bought along a small selection of early .303 rounds. Nothing as early as Terrylee's 89 dated round but there was a MkVI 1914 dated example and a R /|\ L hollow point .303 which was undated.