KYNOCH'S PATENT headstamp .577 Snider?

Is this brass cartridge, with “KYNOCH’S PATENT” headstamp, a normal .577 Snider cartridge, or something else?

Pablo, this is a .577 Snider made under George Kynoch’s No. 4776 patent of November 1, 1881. The case is a two-piece construction with an internal metal cup reinforcement. A really rare cartridge, congratulations!

Thank you for the info, Fede!

Hi Pablo
it would seem, to my mind at least, yours is a middle version of these two.
The upper cartridge goes with the upper headstamp. It is very faint impressed headstamp, but uses a fancy sort of font with large letters. While the lower example has the same headstamp as yours but is a one-piece case, at least on the outside.

VERY interesting. & now I have another to look for, (which I’ll probably never find). & you have two more to find! GOOD LUCK to us both!

The base on yours looks higher than the upper one (.220" / 5.6mm) which also has a slight raised ring around the primer pocket.

Thank you for sharing!
Yes, the base on mine is 7.5mm
Very interesting…

KYNOCH’S PATENT appeared only on shotgun cartridges as far as I know (?) I am happy to bow to superior knowledge on this. Mind you the Snider case is a shotgun case in all but name