Inside-primed 450 round

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 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?

Fiocchi made many rimfire cartridges back in its early history, mostly for European revolvers and such. ( also "cane guns etc).

Most of the early Centre fire cartridges of similar design were derived from the general dimensions of the Rimfires which they replaced.

Doc AV
AV Ballistics.

Looks like an inside-primed .450 Short Centerfire to me.

Chris P. could confirm.

[quote=“Cyberwombat”]Looks like an inside-primed .450 Short Centerfire to me.

Chris P. could confirm.[/quote]

I have this same round and list it as inside primed.

Yep, inside-primed .450 Short Revolver.

Inside-primed 450 rounds with headstamps of:
GG (intertwined)
M.G. & Co.
MG (intertwined)
Leon Beaux
G. Fiocchi Lecco, Piloni
all have identical internal construction.

Chris P.

Thanks for the information.

Any idea what the approximate age of this round is? And what’s the history behind it? Thanks.

This round is listed in the 1926 fiocchi catalog