Electric primed ignitor

I am not at all sure what this was used to ignite. I found a about a dozen in a plastic bag in a bunch of “stuff” from an estate. The owner was a retired Watervliet Arsenal employee for almost 40 years. This appears to be electrically primed. Don’t know if there was any connection of the primers to Watervliet Arsenal. I thought I remembered seeing a thread sometime in the past on something similar but I am unable to find anything on this search engine for this sight. Probably not asking it the right question…

Basic info, large caliber naval gun primer (bag gun, does not use a cartridge case to seal the breech and uses incremental bags of propellant which are ignited by this primer) yours is a combination electric - percussion primer while the one shown in the attached thread is percussion: viewtopic.php?f=8&t=7312&p=51042&hilit=155mm#p51042 . “44” = 1944

Ordnance School Manual, Artillery Ammunition, OS 9-20, Artillery Ammunition Primers & Fuzes, Aberdeen Proving Ground, U.S.1941

this is along the same idea but the case in question is electrically ignited and the “pronged” case mouth does not appear to have been folded or crimped. It almost appears to have been designed to pierce. Naval gun? Did ground artillery use electric primers?

I think that looks like a “combination” elec and perc primer, as shown in BD’s post also. Yes, it was crimped, with the pre-engraved segments that you see post ignition. IF you looked at the closure before firing, you would see the “pie-shaped” engraving on the end cap. I hadn’t considered the function of the segments as piercing the prop charge bags, but I guess it could happen–although in “nano-seconds”! Your primer is probably Navy, at least in design, as it is a “Mark” nomenclature. If it were for ground use, it would be more likely an “M” or “Model” nomenclature. There are/were ground systems using perc, elec, and combination primers, I believe.

The Lock Combination primer has been discussed on the forum several times. A little searching should turn up the threads.

It was also used in a special case for the smaller calibers to test firing circuits and to blow out debris in the bore.


Wow, Thanks all! Really cool info. I wonder now if the primers came from the arsenal? They certainly made the tubes for naval and ground artillery there. I can’t imagine they did any test firing there as the arsenal is right in an urban area. and I am not aware of any test ranges nearby. Probably no arsenal connection at all. Thanks again.

While Watervliet might not have done test firings at full range, they likely did proof testing at short ranges.
They almost certainly would have tested overhauled guns or breech systems, for firing pin/firing circuit operation, possibly using these.

Or, the previous owner may have gone to a naval facility at some time in his career and grabbed a couple of these as cool souvenirs a bit different from the army stuff he was used to dealing with.

He was a quality control inspector. Your theory may be correct.

Had I known then what I know now, I would have taken a full sealed box of those primers when I left my ship for the last time. Of course, my sea bag was already full of all the other stuff I was liberating, and had the sentry bothered to look I’d probably still be in Leavenworth. I still remember lifting the sea bag onto my shoulder and trying as hard as I could to make it look easy, while all the while hoping I didn’t tip over from the weight.