Originally Posted by
No.3
Missed the point there - the primer compounds themselves apparently react with zinc elements (zinc is one of the most reactive metals). Losing the zinc (and there isn't much to start with) means the 'gunmetal' brass the case is produced from is not ductile any longer, just fails. As it's losing zinc inside the case (reaction is apparently something that occurs with the powder being exposed to whatever is in the primer compound) the evidence is mostly internal. Most military ammo has a 25 year design life, or a certain number of cycles, travel hours or time out of the case whatever comes first. We were using some that was 1960's production, most went OK. There's a reason it's been turfed out and sold off, apart from the lack of places using a caliber. I saw some 7.62x54 that was rubbish, along with some weird 7.62x51 NATO (boxer primed but most was hangfire or dud and the cases were rather dodgy - not even worth recovering components).