Deactivating live primers for removal

[MikB]

Penetrating oil has to be of low viscosity and therefore is generally volatile and will evaporate - at best - in a timescale similar to water. WD-40 takes longer, but I have known one case where a primer I'd 'deactivated' with it came to life again later - though I can't remember the exact circumstances.

Slightly heavier oils like light machine oil (eg 3-in-1) have generally worked well on the few occasions I've needed to do this. I certainly haven't tried the hammer test afterwards though!

I think that machine oil is used in inert collectors' cartridges, with the addition of some oily sand or tissue inside the case to maintain the vapour-pressure of the oil in the primer, to stop it evaporating over longer timescales.

Presumably the oil works by reducing the friction between priming compound particles so that less heat is generated by a 'normal' impact, and acting as a heatsink to absorb such as there is. I doubt that it kills the reaction chemically.

Regards,
MikB

[slowcoach]

Shoot from the gun with the muzzle resting on a slightly damp wad of cloth. Catches sparks and residues.
Just a pop, doesn't even scare the dog or annoy anyone.

Don't forget, clean barrel and muzzle after!

[RichardH]

Interestingly that based on that (which sounds very plausible) much of the "inert" collectors ammunition out there would count as live ammunition under the definition of the firearms act.

[MikB]

Interestingly that based on that (which sounds very plausible) much of the "inert" collectors ammunition out there would count as live ammunition under the definition of the firearms act.

Well, I'm referring to the collectors' rounds I had as a teenager 40 years ago! Oily sand or tissue was practically always there then in place of the propellant charge.

There might be other methods now, but I reckon if there was an easy chemical kill, there'd've been no need for the article quoted by Foxshooter!

Regards,
MikB

[martindl99]

I made up an "inert" 577/450 for a friend of mine. I soaked the primer ( CCI ) in an engine oil bath for several days, fully confident it was dead. My friend popped it into the chamber, squeezed the trigger and BANG, it went off. It certainly taught me a lesson.

[pmercer]

I often need live looking rounds for display purposes so I've done a fair few tests myself on 'killing' live primers using various oils. (Never tried water though.)
I also found that a large percentage of primers stay live after oiling/wd40ing. This shocked a lot of my shooting pals who swear oil works. Incidentally, none of them have tested the rounds they've made inert!

[andrew375]

I just gently push the primer out with the decapping pin. Never had one go yet, but I keep my hands well out of the way as well as wearing safety glasses. Primers are designed to work with a sudden concentrated application of force. If it were otherwise then they would be going off when you tried to seat them.

The idea of making a primer inert with WD40 is just a myth and has been disproved many times. The main thing you have to realize is that primers are sealed with a lacquer during manufacture. So first thing you have to do is break down this lacquer seal with a solvent like acetone or cellulose thinners. Even then WD 40, which is just a light oil with waxes in dissolved in it, failed to destroy the priming compound.

To be absolutely certain a primer is dead the only way is to fire it off. Then clean the gun as it will leave a lot of highly abrasive residue in the barrel.