Cartridge Case Identification Help


I’m a first time poster and am requesting some assistance in identifying this cartridge case. My neighbor found it on the grounds of the old Camp Grant (1917-1946) here in Rockford, Illinois. She asked me to identify it and I have a guess but I’m not knowledgeable enough to give her a definitive answer. So here I am, hat in hand, asking for assistance.

When I first laid eyes on it, my immediate guess was 30-06. After measuring the case and spending a couple of hours doing some research on the net, I’m a little confused. The case measurements are close to those of a 30-06 but are off by several thousandths.

Measurements of this case:
Case Length - 2.485"
Neck Diameter - 0.330"
Case Diameter - 0.456"
Rim Diameter - 0.466"
Rim Thickness - 0.050"
Head Stamp - U.S.C.Co, two stars, the number 18

I want to know:
1.) Is this 30-06? If not, what is it? If it is, why are the dimensions so much different than what is posted on the web for a 30-06?
2.) I know U.S.C.Co is U.S. Cartridge Co. but what is the 18? Is that the year the cartridge was mfg. or does it denote something else?
3.) Is there anything else I should know about this cartridge case?

Thank you all in advance for sharing your knowledge.

Forged on the anvil of discipline.
The Few. The Proud.
Jerry D.


That is a .30-06, but the case has been used in the manufacture of a standard blank cartridge.
It looks like a Model 1909 Blank to me. The case was probably a reject case, as I don’t think
this style of case was made specifically for blanks at all. Could be wrong, as am out of my
field here.

Those cases with both the stake and heavy ring-type primer crimp are normally for aircraft
machine gun use.

John Moss


Yes, it is a .30-06 case, evidently used for a blank (denoted by the crimp around the neck a bit behind the case mouth). It was made in 1918 by USC; the stars indicate the Hooker extrusion process was used in working the original material. If this case had been loaded as a conventional ball cartridge the fired primer would be much flatter and the firing pin indentation better delineated. [I saw John’s post before finishing this one, but will leave it in case it’s of some use] Jack


Jerry D.

Thanks for having the confidence to visit and post on the IAA Forum. Welcome and come back again. Page out to the IAA main webpage to check out the IAA (top and right menu bar item)




Welcome to the Forum!

Dimensions may vary from those listed due to the fact that it is a fired case and also it looks to have been in the elements for some time.



Thank you all for the information and the warm welcome. I included the picture of the neck because the ring around it jarred one of my last remaining brain cells and it looked like the blanks we used for M-1s in ITR. Thanks for confirming that last brain cell is working.

I’m guessing the cartridge was used in training at Camp Grant. Giving consideration to the condition, even though mfg. in 1918, it probably was not fired until much later than WWI. My guess would be shortly before or during WWII.

Forged on the anvil of discipline.
The Few. The Proud.
Jerry D.