Any interest here from German 7,9 collectors on zdh30 primer

Some of the posts concerning German 7,9 fired cartridges as of late, have touched on fired primer condition in relation to what the original loading was in the fired case. Mostly referring to the German copper zdh30 which was used in service blanks, but was also used in full power ammunition for a few years before being deemed not of service grade for full power ammo. I have quite a few of these loaded cartridges that utilize these primers (zdh30) and would be willing to test them and post the photos for people here to see. Since most of this seems to swirl around SS contract loadings, I would propose to use many of the most common weapons procured by them. I figured I would use the rifle 98k, VZ24, & ZB26 LMG. There were certainly many others but this would cover the most common. The ZB26 shares a firing pin impression with both the ZB30 & ZB37, both used by the SS. If there is enough interest in this project, post and let me know and I will get things ready. Happy New Year! JH

Hey Jim,

I would be curious.

What procedure did you have in mind? When I think of the Zdh 30 primers in combat experiencing “frequent failures” I have often wondered what that implied. I can’t imagine the Germans didn’t test the primer quite a bit before making millions and millions of rounds of it and then shipping it out to the fight.


From what I understand (Kent and also Windisch, Brandt et al), the
ZdH 88 was a Mercuric, Corrosive primer ( Mercury Fulminate, Potassium Chlorate, etc) and was used in German 7,9 from 1888 to almost the end of WW II ( Any Box Labels with ZdH88 in 1945?).

The Development of Noncorrosive priming Compounds by Germany had been started even before WW I, and then further developed in the 1920s. The Germans sought a means of removing Both the Mercuric And the Corrosive Elements in the priming Compound, and substituting them with Lead-based Primary Ignition Compounds

IN 1930, they produced the ZdH30, which was Noncorrosive…but was it also “Non-Mercuric”?

Whatever the problems in the ZdH30, they were obviously overcome by the ZdH30/40, also Noncorrosive and definitely NON-Mercuric. The Cup material was also changed to Zinc Plated Steel, and this primer was matched to steel cases (Mostly the Grey “Bonderised” Type.)

As to the old Saw about “Mercury makes cases brittle”…the German experience puts that furphy to sleep quite easily. Germany Reloaded brass from ZdH88 cases from 1888 till the mid 1920s,( Ball and Blank) without any signs of “Case brittleness”…where is the supposed “Mercury Amalgamation” which supposedly caused the brittleness?.,… Many of my earlier Posts on this matter sheet the blame home to “Age or Season cracking” of brass which had NOT been “Neck and Shoulder” annealed Prior to Loading…this was especially so in Cordite (British) Loaded Cartridges, which were neck and shoulder sized AFTER Loading with Cordite…IN order to prevent reloading of British Military ammo (BY Civilians and Natives) the British spread the “furphy” that the Mercury in the primer weakened the brass, making it it unsafe to reload…And the US took up this subterfuge, to increase fresh ammo sales (Even though the US reloaded a lot of Formerly Mercury Primed Brass in the early days, before the adoption of the Corrosive, but NON Mercuric FA70 primer. US cases still split, because they were not annealed (N&Sh) until about the mid 1920s.).
Note the Billions of rounds of .30 Cal made in WW I, which began “age Splitting” in the 1920s…they were NON-Mercuric primed, but also NOT annealed in manufacture…WCC introduced Neck and Shoulder Annealing to US Ammo making in 1916, with the Tsarist 7,62x54R contract, as the Russians insisted on this procedure to avoid “age/season cracking” in extremes of Russian climate…the US still persisted not annealing cases till the Semi-Auto rifle developments of the early 1920s, which made N&Sh- annealed cases essential to proper function.

The Only Scientific Connection between Mercury and Case Splitting was that Mercuric Nitrate solution was used to evidence “Age cracking” IN loaded ammo as an inspection process…The neck of the case was dipped in a solution of HgNO3, and allowed to sit for a few minutes…then removed…depending on the time it took for an incipient neck crack to open up (Internal stresses), decided whether the Ammo was condemned or not. NOTE that this is a form of Stress-induced Acid Oxidation of the metal, along stress lines, allowing for cracking to occur…a thing which in improperly annealed cases, would happen naturally (without Mercury) anyway over time…the Mercury Nitrate test simply hastened the process.

Getting back to German primers…in addition to the Rifle cartridge primers, I suppose the P-08 Primers were of similar composition ( Mercuric & Corrosive pre- and during WW I, NON-Corrosive/Non-Mercuric from the late 1920s to 1945?

ANY further Documentary Info on German Primer Composition over the last 140 years???

Doc AV

PS, similar “Mercuric primer use” occurred in many countries which regularly reloaded fired cases (Ball and Blank) without any bad effects on the cases ( Holland, Romania, Italy, etc.) Prior to WW I.

A fact that might usefully be added to this discussion is the employment by the German armed services of blank cartridges in 7.9 m/m before the first war with noncorrosive priming. They did not, apparently, regard those primers suitable for ball ammunition. This was mentioned by Dieter Storz in his Gew. 98 book. Jack

Doc, the zdh30 was both noncorrosive & non-mercuric. JH

My knowledge of 8mm primers is very limited.

The existence of the primer 08 and the 08/40 is known. Think they had the same improvements as the 7,9 primers.

Some factory’s used a kind of primer with a small circle in the primer. By civilian rounds it calls a Synoxid primer, noncorrosive & non-mercuric. Unfortunately I cannot tell you the name.

Lew… John…Help

It is the primer on top.


Regarding mercuric primer compositions, I had understood their greatest weakness was not so much amalgamation of brass but very limited shelf life, especially at elevated temperatures. Mercury fulminate does not contain metallic mercury, but rather is a chemical compound containing mercury. As mercury in a free metallic form would, I think, be necessary to form an amalgam with brass or copper, I could never believe that case amalgamation occurred as a result of firing mercuric primers.

I believe that the decomposition of mercury fulminate as the primer fires releases small quantities of metallic mercury. It’s this mercury that degrades the brass. It may also be the case that tiny quantities of metallic mercury are present in improperly compounded mercury fulminate. Jack

I recommend James Smyth Wallace’s book, “Chemical analysis of firearms, ammunition, and gunshot residue” published 2008, 291 pages. Chapter #8 has a wealth of information for those interested in the actual chemistry and problems associated with mercury in priming mixtures related to brass (not copper) cartridge cases going back to the 1850’s as well as the history of it’s use well into the 1950’s in small arms ammunition primers. It covers the advances & failures of various other priming mixtures from 1850 until present as well. No “old saw or furphy info”, just the science. ISBN 978-1-4200-6966-2 JH

Dutch - those primers with the impressed “O” on them (you are correct, the “O” indicates Sinoxid, Dynamit Nobel’s name for a non-corrosive commercial primer) are from Dynamit Nobel - I do not know the military eqivalent designation, if there even was one. Pistol Ammunition made by RWS and GECO from the early 1930s, I think, and until the end of WWII, will have this marking on the primer. It is found with cartridge cases with commercial headstamps, including some anonymous (no marking except the caliber, or no headstamp at all), amd also with various Police headstamps - special headstamps, or military-coded cases. I don’t think any of the military headstamped cases so-primed, usually found with red seals, were actually provided to the military, but I could be wrong. You also see it with cartridges with other company headstamps, but probably actually made at Geco. I have a .32 auto round with “P” factory designator (presumably “Polte”) and the Sinoxid primer from RWS. Of course, it is also possible that they sold the primers to Polte.

Primers are an interesting study. I wish I knew more about them, but trying to learn about all the different primers used in all the different pistol cartridges (in my case) made around the world is a mind-boggling proposition. On most of them, there is little literature available for study.