Help identifying

My father-in-law left me some bullets I cannot identify. Need help. Thanks

here is the correct link: … 7766_o.jpg

They look like .56 Spencer rimfires to me (who knows nothing about rimfires!)


Thanks TonyE. THAT WAS FAST!!!

The two on the ends were made by Winchester. Someone more familiar with rimfires may be able to tell you who made the center one.

I can help on the center cartridge, but I need micrometer inch dimensions and a better picture or the head.

Base (not rim, but just above)
Total Case length


These are not .56-56 but necked case variations of the .56-52 Spencer. The ones made by Winchester are of the Stetson 1871 patent type.

If I had to guess, I would say the middle one was a 56/52 U.S.C.Co.
But I do not like to guess. Mic. measurements are better.


It’s obvious that one of those cartridges is not like the others.

If you have ever tried to collect the big rim fire cartridges, one thing becomes very obvious, very quickly. Uniformity of dimensions did not seem to be a very important factor to most manufacturers. The Spencer 56-52 cartridges can vary in rim, base, neck, and bullet diameter, as well as case length. And, I don’t mean a couple of thousandths. Even the experts have a hard time identifying some of them, much less us amateurs here on the Forum.

Good Luck.


From the chapter on 56-52 Spencer cartridges in Charles Suydam’s book The American Cartridge, 1960, revised edition, p127; a cartridge similar in appearance to the middle cartridge from above is shown. Unfortunately it is listed as unidentified as to maker. As Joe indicated above some case dimensions may be of some help.

Are there any marks impressed into the base of the center cartridge ie. dash marks, single line, small triangles etc.?

In the book The Rimfire Cartridge in the United States & Canada by John Barber, 1987, there is a chapter on rimfire case tool base marks; for a time these marks appeared on some rimfire cases as part of the manufacturing process. Barber lists some of these marks and attributes them to specific ammunition makers.


A little off-topic but related - Back many years ago when I was into Indian Wars history, I did a lot of metal detecting at the different battlefields in Montana and Wyoming. I would find all sorts of fired rimfire cases for the big (.50+) calibers and I naturally assumed that the Indians had a wide variety of rimfire firearms at their disposal. That seemed odd. But as I learned to ID the cases and the different firing pin marks, I realized that most of them had been fired in Spencers. So, even though the cartridges varied in size, a lot, they were all close enough to be fired in the one firearm that most Indians were able to get their hands on. I imagine that the traders who sold them the different cartridges knew better, but a sale is a sale.


Distinguishing between a Winchester-produced 56-52 and a 56-50 of the same make is not a task for the faint of heart, nor for those imperfect character. Had Winchester made their 56-50 with the original long case it wouldn’t have been much of a job, but no, they chose to shorten it to the same length as the 56-52. Every time I read up on how to distinguish the two rounds I get it straight, only to forget within a week. Maybe that one in the middle is one of the French cartridges. Jack


Yes, that is my point, The Rimfire Cartridge in the United States & Canada by John Barber, 1987. He also lists some foreign manufactured rounds. It is the best book out there still as far as I am concerned. People keep trying to repudiate what he published, but it is pointless, as most of what he has reference to is cartridges out of original boxes. I have always been satisfied identifying cartridges with his publication using measurements and the pictures in the book, along with illustrations. Some more detailed pictures and measurements and I will tell you what it is most likely, according to the publication.