The .320 Extra Long CF is something of a mystery. It is not listed in any Eley Brothers catalogues between 1870 - 1914 (though I don’t have every year). BUT it is listed in the Eley Loading Book kept at the factory until 1923 as ‘.320 Extra long CF’ using the .300 Rifle case with 14 grains No.6 Carbine Black powder and 80 grain conical lead bullet with heel and one cannelure - no wad over the powder. Of course they could have just kept the load on record and never actually loaded or sold this cartridge. I have found no evidence of Eley manufacture.
Kynoch list the ‘.320 ex.lg.’ with 80 grain bullet and 10 grains Black Powder in their 1891 catalogue. Kynoch does not list it in their 1882, 1884, 1898 or later catalogues.
Note that the .320 Extra Long uses the same 80 grain bullet as the .320 Long RR. The case for the .320 Extra Long and the .295 or .300 Rook Rifle are identical. [Note reference to using the .300 case in the Eley Loading Book] The difference between the two cartridges is the heel type bullet of the .320 Extra Long and the internal lubricated .295 or .300 RR. I suspect the .295 or .300 RR brought out by Holland’s in 1882 was a ‘modernized’ version of the .320 Extra Long. [Note however that the only reference I have found to the .320 Extra Long was in 1891 - nine years after the intro of the .295 or .300 RR]
I would like to find a box label for this ctg. Why your interest Ado? Have you found a .320 Extra Long in Chile? In 35 years collecting I have only found one - in England. It’s an easy cartridge to miss. My example has no headstamp.
Attached copy drawing Eley .300 RR (&.320 Extra Long) case dated 1906
and photo’s my example .320 Extra Long (on left) and .295 or .300 RR on the right.