Dark Skies wrote:You seem to have done a 180 from your original stance:
"I'd be wary about putting primers into a steel safe"
No, that was my original position and is still the same. Should a large quantity of primers detonate en masse, the potential damage is enhanced by storage in a strong metal container. That is because it confines the expanding gases and if the container walls fail under that pressure you will get a much nastier result. After all that's why a standard artillery shell, aircraft bomb, or hand grenade use a thick iron covering around a relatively small explosive filling - the mixture of pressure containment allied to the resulting lethal dispersal of metal fragments, usually (but inaccurately) described as 'shrapnel'.
.......... and primers
are scary items! Here's a cautionary tale from my own experience which I think Dromia might appreciate, but is a serious example of 'Do not do this yourselves at home' practices which I'll pass on to the unwary.
Around 20 or so years ago, maybe more, I bought several hundred loose surplus mixed-make 7.92XS57mm sS rounds, £6 or £7 /100 so it has to be a long while back.
When I sorted them out, I found an old Kynoch 7.65X53mm Mauser soft-point round, which I now had in my possession illegally as I had no slot for such on my FAC. Sorting that was easy enough - two secs with the bullet puller and dump the powder.
But ... I wanted the round for my inert ammo collection, so the primer had to go. Being 1960s Kynoch, it was a Berdan primed case so a gently applied decapper die on the press was no good. Couldn't fire it as I didn't have a suitable firearm and it wouldn't chamber in anything I did have. I could have soaked the case and primer in mineral oil ... but I already knew how hard it is to completely deactivate primers. Easy enough to degrade their performance, very hard to 'kill' them.
So, I thought and thought and rummaged around in my kit and settled on a 308 Win Lee Loader kit. Use the main part as a chamber, the decapper rod/pin as a rough and ready firing pin held against the primer and tap it with a hammer. Having popped the odd primed case in rifles before, you get a sharp crack, maybe even a bit of muzzle flash, that's all.
BUT ... who'd forgotten that in commercial ammo (as opposed to milspec with its crimped-in primers) the only thing that holds the primer in the case is the bolt?
Anyway, into the garage. Tap the case into the 308 'Loader' so it's a tight fit, hold it facing down against a concrete floor, place the rod/pin onto the primer also holding it with the left hand using thumb and one finger; take the hammer with the right hand and hit the back end of the rod with a hammer.
It worked alright, too bl**dy alright by far. There was an earsplitting 'crack' - my ears buzzed and whistled for an hour or two afterwards, and it probably did some permanent damage. My left hand and fingers hurt like b*gg*ry - akin to having a large 'banger' go off in your hand for those old enough to remember this variety of pre HSE-Commission firework. The Lee decap rod was blown clear out of my right hand and the primer ricochet'd around the garage fortunately missing my face and even more luckily my eye in the process.
The moral of this tale is don't muck around with primers. A 5K 'brick' of LRs or LPs likely contains a pound weight or thereabouts of primary explosive - and it IS explosives not propellants, pretty powerful stuff at that.