.60 Cal. Pressure Test Case, W.S.M. CO 1942


Found in a junk box at a gun show about 10 years ago and recently rediscovered in a box of stuff while looking for something else is this fired .60 Cal cartridge case apparently used in a pressure test. Manufactured by Worchester Stamped Metal Co. in 1942. From the chapter on caliber .60 machine gun ammunition (History of Modern U.S. Military Small Arms Ammunition, Vol. 2, HWS) W.S.M. Co. began supplying test cartridge cases in 1941 and going through much of the war.

I have not yet cleaned the case so that the scribe lines and powder burn around the hole in the side of the case are readily apparent in as found condition. I assume the scribe line on the case (noted by the blue arrow in photo below), bisecting the drill hole in the case wall was used to then scribe a line across the cartridge case head so that when the cartridge was loaded into the pressure test barrel the hole in the side of the case could be aligned correctly in the pressure test gun.

From an earlier thread here on the Forum: .60 cal

"…the cartridge…headstamped CAL. 60 LOT 7663 W.S.M.CO. 42 is one of the developmental cases with more taper - the shoulder measures 1.003" rather than the 1.045" - 1.050" of the later examples. "

Some other WSMCo. headstamps:

< .60 Cal "FA 45" dummy

The headstamp posted by “D” or “dak21” shown above is also shown in HWS Vol. 2 on page 187.

The number of cartridge cases in a lot must have been very small and/or perhaps different case types (T#) were assigned a specific range of lot numbers???

Additional comments, information, corrections are welcome.




Nice early .60 Cal. item for having been in a box of “stuff”! Thank you for sharing.

Don’t think I have seen one before though it makes perfect sense that many pressure tests were done during the development of the .60 Cal.



Great case Brian.

Here’s one of the earliest .60 pressure test cases - dating from ca. 1939,

And a couple of later lot numbers for WSM manufactured cases.

a fired case

This one is neat with a reversed primer cup crimped in. Green tip over black projectile.

Same lot as above, no primer.


Part of a letter to Jim Tillinghast from Frank Hackley which I just came across yesterday.

And while not a pressure test case a F A 45 Percussion primed proof or high pressure test loading.

My W.S.M.Co 43 date noted in the link above is like Paul’s with a crimped-in reversed primer cup and a black bullet (like Paul’s) but with a white tip.


Dave, Paul, Pete,

Thanks very much for the great info and pictures. I’ve never seen the reversed empty primer cup dummy rounds until now.



First, thanks to Pete for Frank Hackley’s list, posted above (over a year ago!)

Has anyone got or seen a LC headstamped Cal…60 round or case? I would like to know the “format” of this headstamp and I did not see it in HWS Vol I, II or III. Specifically is the LC separated (eg: “F” “A” “44”) or together (eg: “SL” “44”)? I am trying to replicate the headstamps in my list and I want to be as accurate as possible. TIA. Taber