50 Cal Rimmed Cartridge

Can anyone please provide any nformation on the rimmed 50 cal cartridge shown in the picture. Initially I thought it was an unfinished case with a projectile inserted, but it has a normal primer and is loaded?

Thanks in advance.


Could be a rimmed Soviet 12.7mm round, about 107-108 case length. What’s the headstamp?

From the Look of the “unfinished” rim ( rounded) it looks like a Normal .50 case before being Rim and Groove Turned ( cases are Made with a “Headed rim” during “Head forming” so that the Rim can be used for indexing in the die tables of the Case forming Machine…then when the case goes for Trim and Rim Turn, the formed case is made with the finished extractor groove.

I have samples of “Rimmed” 7,62 and 5,56 made on SCAMP machinery back in the mid-80s, here in Australia, when they were trialling the Gulf+Western SCAMP system.

If it is “Loaded” could it be for Load testing Purposes ( Pressure Gun?) where the cartridge Powder Load is tested, and a Rimmed case would facilitate both Headspacing and extraction in the Pressure Barrel?

What headstamp (if any) is on the case? ( HS usually applied to .50 cases after head turning.)

BTW, the 12,7x108 is visibly Longer than a 12,7x99 (BMG) cartridge ( by 3/8th")

Doc AV

Ian, a ball loading with this case type was made by Kynoch without a headstamp, but I don’t know for what purpose. Conjay Arms reported these back in 1975, and its description was: “.5 Cal. Flanged Ball Ammunition, Bullet Weight 426 gr, MV 920 m/s”. As you surely know, this company had at hand an amazing variety of Kynoch test loadings. Regards, Fede.

Does it have a headstamp?

I have several unfinished cases (the rim has not been trimmed) & some have a friction fitted bullet. The primer pocket on yours might not have been vented, but the case mouth does look crimped. So all the above is just food for thought.

Jon, I am very sure that this is no 12.7x108R ShVAK.

Buster, it might be helpfull to show the case head.

I also have one of these rounds. Here is a picture of the head.

I’ve seen a label at Woodin Lab that I believe is associated to this round. It was several years ago and I can’t find a picture of it (the name was .50 Flanged or .50 Rimmed), but it removed my suspicions that this was a round made by someone from unfinished components.



it seems that your round is slightly different from the other one.
I think I see an extractor groove on your round which is missing on the other one.

So, two different cartridges ??


Thank you all for your helpful replies, I should have put in my original post the round did not have a headstamp. I was going to put a picture of the head up, but it is identical to that which Paul has shown above.


Busters looks like the case mouth is crimped, but Paul’s bullet looks to be friction fitted, Is that so?

Pete the bullet is a push fit the same as Paul’s, the photograph is slightly misleading.


Does anyone have the original pictures?

Ian’s photo of the rimmed .50

Paul Smith’s photos of the rimmed .50


Thanks. Did you have these saved, or is there a way to get them from photobucket directly?

I had the thread saved.