20mm primer - live or dead?


In the image below is what I think are some 20mm headstamps of some sort, but are they live or dead? Is that ring mark in the center of the primer an indication of being struck or deactivated? Or is that just how those are supposed to look?


electric primer



Those are electric primers and I think the ammunition is the 13x64B rather than 20mm. I’m not sure if there is much of a mark made on fired primers of that sort but most I have seen are unfired and inerted in some fashion.



Even on fired electric primers you will see a firing pin strike, just doesn’t look the same as a strike on a percussion primer. Those look unfired to me.


Thanks everybody, it’s from a seller who doesn’t seem to know what he’s got, he had those listed as .50 cal rounds here: http://www.gunbroker.com/Auction/ViewItem.aspx?Item=189813418


…and the yellow painted ones are HE.



DKConfiguration–These look unfired to me, either Live or Inerted. I have worked with thousands of 20mm Electric Primed ammo used in the M61 Gatling Gun. The fired cases from this gun always showed a very shallow dent from the firing pin/electrode, usually looking like the mark left on a primer that has been chambered a number of times but not fired in a bolt action rifle. The firing pin/electrode, at least in the M61, and I presume in most electronic primed systems, does not use a spring loaded firing pin like in most guns. Instead, the electrode is a block that moves in a track that brings it into contact with the base of the primer. It only has to make contact, not indent the primer to fire it.


Out of curiosity, what is the voltage and current needed to fire such a primer?



Don’t have any info on the German electric firing guns but found a reference in a TM for the US M24 20mm that seems to indicate that minimum DC voltage was 160V. There was no indication of what amperage was involved.



If I remember correctly, the current is a variable depending on the electrical resistance of (in this case) the electric primer and the applied voltage by the formula “resistance = voltage / current”. You can measure the current but not predetermine it in a firing system or so. However, I’m not an electrician so I stand corrected.