I found this cartridge while helping my father clean out my late great-uncle’s house. Not sure exactly what it is.
This is it next to a Federal .22LR:
Here’s the headstamp:
And here’s a shopped version of the headstamp to make it readable:
The headstamp reads “450” at the bottom and “G.FIOCCI -LECCO” at the top.
It appears to be a rimfire cartridge.
I asked about this cartridge at TheHighRoad.org forums, but no one there was sure exactly what it was and one of the posters there thought that you guys would probably know.
Couple of people there thought it was a .44 rimfire, others thought that perhaps it was a .450 Adams, but when I looked up the .450 Adams, all of the examples had distinct centerfire primers.
So, anyone have any idea what this is?