Apparent corrosion around primer




White oxidation around primer cups is common in Potassium Chlorate based primers (see this regularly in US .30/06 of Wartime manufacture.)
It is due to deliquesence (the absorption of atmospheric water by a crystalline chemical compound, in this case, KClO3.) and the liquid then oozes out of the primer pocket and crystallizes outside, giving this white effloresence.
A sure sign that the primer is effectively Dead.
The Only Canadian primers to use (AFAIK) lead styphnate were the DI (Defence Industries) Boxer primers in .303, 7,9 and 9mm ammo.

Lead Azide is only used in safety detonators for High explosive charges.

regards, Doc AV
AV Ballistics.




Just to clarify possible confusion re hst photo’s of primer corrosion. The ‘K.44 F G II Z’ hst has a green annulus to ID the armour-piercing tracer load.


Isn’t the F for semi AP and FG for SAP Tracer?



Yes, FG is S/AP Tracer, If it was full AP it would be K.44 W G II Z. I’m not sure if such a round exists. Possibly not.


gravelbelly & Falcon - I think you’re missing the point. The point I’m trying to make is that the green annulus in the photo is not corrosion from the primer as inferred by the text - its a deliberate colour code - whether for AP or SAP!!! Regards JP-C


I missed that too. Churchill said " 2 peoples divided by a single language". The inference was not implied just a random accident of ammunology. I don’t recall ever seeing green corrosion from the primer. It is usually seeping out of the neck crack. NOW WE KNOW WHY, something confusing about crystals.



Point taken, I have a habit of being pedantic sometimes. See you at Bisley in February.