Unidentified cartridge case (revolver type, about .42 Cal)

It is a brass case with a Berdan primer with 2 flash holes (copper primer cup). This case has no headstamp of any kind. It has a very old looking domed head. It appears to have been pulled and looks to have containted blackpowder propellant as the primer is unsnapped and it has blackpowder type corrosion on the inner case walls. The case also has a hole dorroded in it, and the case may have swelled where the blackpowder absorbed moisture.

Calibre: About .42" (11mm) (I can’t say for certain as the neck is mis-shapen).
Case length: 1.12" (28.5mm)
Case dia. at mouth: Neck to damaged to give meaningful measurement, wall thickness obout 0.012" (0.3mm)
Rim thickness: 0.4" (1mm)
Case outside dia.: above rim: 0.479" 11.9mm
Rim dia.: .530" (13.46mm)

Cartridge case from side: (9mm Para round for scale):

Case head:

Does anyone have any idea what this is? I would be grateful if you could identify it.

Looks like a 44 Colt or a 442 Revolver long case.However the 44 Colt has a bit smaller rim diam,and the 442 Revolver long is a bit shorter.

10mm Mauser long ?


I checked some data I had on the specifications of the .44 Colt and .442 Revolver, it doesn’t appear to match either. I can’t find any measurements on the 10mm Mauser long.

Something I have just noticed is that the rim diameter of this is identical to that of a .410 Shotshell. Could it be an attempt to make some sort of revolver calibre from a cut down all brass .410 Shotshell? I also think this may be the case as it looks like the base MAY have had a headstamp removed using a lathe and emery cloth.

Actually I have a 410 / 36 gauge cartridge with the case cut off to 33 mm.
I don’t know if existed 28-33 mm long commercially-made 410 shotshells.Maybe they are homemade reduced loads

[quote=“Pivi”]Actually I have a 410 / 36 gauge cartridge with the case cut off to 33 mm.
I don’t know if existed 28-33 mm long commercially-made 410 shotshells.Maybe they are homemade reduced loads[/quote]

28-33 mm long commercial made 12 mm shotshells don’t exist.

It seems from your picture the rim has a round shape, doesn’t it ?

And when you say 1 mm rim thickness it is a little bite too small fror a shotshell, except if the guy trimmed a lot the base.

13.46 Rim diameter is Ok for a shotshell.

I was thinking that someone may have cut down the case and modified the case head of a .410 Shotshell to try and make some sort of obscure revolver round. Would the thin case walls of a shotshell be okay in terms of pressures for a blackpowder round?

I got another one of these cases off the same guy (he only had 2), this one is not expanded, and has no primer cap. What I thought was a corroded hole was drilled in the case wall on both of them for some reason. A more accurate inside neck measurement is about .435" (11mm)

Anyone have any idea on this round? I ran it through the “ammo guide” site, that came back with “no cartridges matched”

It looks like a shortened Eley all brass .410 shotgun rd and the measurements you have given are close as well.

Can you see the photo?

I am currently having trouble accessing anything i’ve hosted on that yahoo thing through my own connection. I has also thought shortened .410 shotshell, I wonder what calibre someone was trying to make.

Im not an expert, not even close…but I read alot. LOL

I have read about a 12mm Sellier&Bellot 30mmm long on another forum but it was Lefaucheux ignition. This can explain the hole if it locates at the base.
IMHO it look like a 12mm centre fire case reformed to 12mm S&B.
hope this hleps.

This is an image of the 12 x 30 mm S&B pinfire, but it’s a rimless-grooveless case of brass and cardboard construction.

It is definitely not a pinfire cartridge, the hole is about halfway up the case. Every cartridge case the guy I got it from had had been drilled to prevent re-use, even though that is not a legal requirement in the UK.

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