6mm Lee Navy, also known as the .236 Lee, .236 Navy, or .236 Winchester, was adopted along with the Lee Straight Pull rifle in 1895.
It used a 112-gr. jacketed round nose bullet that was, like many of the 6.5mm military cartridges, very long and had ferocious sectional density, meaning that it was very low on wounding power.
It didn't make it either as a military cartridge or commercially largely because the powders available then simply weren't right for such a small bore high velocity (relatively speaking) cartridge.
Realistically, the 6mm Remington and .243 Winchester can't do anything this cartridge couldn't.
Winchester did use the case as the basis for the .220 Swift.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.