HELP? 8mm what?

It is a steel case. Very heavy case.
Bullet 7.72 mm,
Case length 83.37
Dummy? Primer looks real.
No headstamp. Head was filed by some one rust removal?
Any one know what it is?



Could it be something made up by someone to look like a cartridge, with a genuine bullet pushed into the neck? The “case” could even be solid steel if it is heavy, and the lack of headstamp also supports this theory. Still, that is probably NOT the right answer. Have you thought of pulling it to see if there is powder?

On the back side of the neck is a single round divot meant to hold the bullet in place, to pull it would most likely ruin the cartridge. It is heavy enough to be solid steel. A dummy perhaps but for what? Vic


If this round is solid it could possible be a round used to check head spacing.
It looks like it may be from around the time of the war. Could have been issued to armorers to check rifles when they field serviced them .These types of rounds were made for a lot of different calibers. They are basically a go -no go gauge.
Been out of firearms a while so I maybe wrong.

That sounds like a good answer but the big question is for what? I have nothing that gives me those measurements for any type of cartridge. Thanks Vic

Have a couple of reference books to look through before I go out on a limb with an opinion.
If this was used for head spacing then the diameter would not be critical the length would be. If the round chambered and the bolt closed then the head spacing was to long,the rifle would then be finished(the rounds would be pushed up the chamber causing a misfire) if the bolt would not close the chamber was not worn out length ways.
Not an expert on military weapons but was there not one of the combatants in the first or early second world war using an 8 mm round?
Maybe there is some one out there with an opinion on this theory:)

Putting on my shooter hat.

GO (Min bolt face to shoulder length, chamber is deep enough) and NO-GO (Max bolt face to shoulder length, chamber is to deep) gauges normaly stop at the shoulder (or just above the belt or rim on those types of cartridges).

Bulleted designs (like this one is) are normaly “action proving dummies” used to test the operation of the mag, feeding system, extraction and ejection. They can also be used to safely train people on how to load/unload a weapon.

However the presence of a primer is not somthing you would expect to find on a proving dummy, due to the potential for firing pin damage (unless it was added later??)

Archer - lots of countries used 8mm weapons during WWI and WWII. However, none used an 8mm weapon with a 83.37mm case length. The German 8mm (7.9 x 57) Mauser was with a 57mm case length, in the normal range for Rifle and Machinegun cartridges of the time. Our .30-06 was one of the longest of the military rounds for normal rifles and machineguns, with a case length of 63mm.

It certainly is a strange cartridge. The only rounds I know of about that calibre which are as big as that are some of the 1930s anti-tank rifle rounds, like the German 7.92x94, the Polish 7.92x107 or the Spanish 7.92x87, but this isn’t any of those that I know of.

In any case, if it’s military the round-nosed bullet implies a date of around the beginning of the 20th century.

The odd thing is, it appears that this “cartridge” is loaded with a RN lead soft-point, which means it would be a sporting/hunting rifle cartridge, not a military one; it certainly wouldn’t be North American (though the proportions look sort of “280 Ross-ish”), and I can’t think of any British or European cartridges that are even CLOSE to the measurements given. (?)

Well Vic I may have been wrong but look at all the interesting information that came forward. Hopefully some one out there has the right answer for you.

There is a 7,9X85 unknown experimental (Woodin 1 279) but I have no image to compare it to. My first thought on see it was that it is a decorative item, but pulling the bullet may tell you more.

It has been a while and no real answer has come up . With all of the new readers I will try again.

did you check if the base/rim dimensions are close to any known cartridge?.
There is also a 8 x 87 spanish cartridge but it is longer and hasn’t got the very sharp shoulder of your round.


Hi Vic,

     This is a FANTASTIC .322 Rigby experimental unknown armourers dummy variation with the already known extra long case (83 mm). The bullet seems to be the same as the experimental .322 Rigby with 2 3/4" (70 mm) case but the diameter seems to be too small. Plese check it.

     Can you post the complete measurements of this cartridge? 

:: Please, don’t forget to including body lenght, neck lenght, rim thickness and shoulder diameter.

Fede: Sure can, you have been the only one with a clue as to what it is actually used for.

total loaded length 101.6 mm
bullet at the base 7.70 mm
head diameter 14.99 mm
diameter at shoulder 12.91
almost rimless but diameter at web is 14.88 mm
case length 83.44 mm
neck length 15 mm
shoulder to base 66.96 mm
single stab or pin in the neck secures the bullet
shoulder and neck seem to show a very slight milling marks
very heavy so very possible solid iron case
Thanks Vic

This is not a Rigby .322 dummy - blt diameter would be .3295L - .3305H (inches). Also caselength would be 2.885L - 2.90H inches (73.68mm). Total loaded length would be 3.73L - 3.75H (inches).

Hi Vic and John P-C,

I'm not talking about the 73,5 mm case but the .322 with a 83 mm case version for an unknown (to me) Rigby magazine(?) rifle (this case also exist in a .350 caliber brass & wood dummy). However, the case measurements reported by Vic are also different. It may be another Rigby experimental, but I don't know wich one. Maybe I'm on the wrong path.