This article was written by a guy called Andrew Poe, he is an american with considerable firearms experience

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How to kill a primer?

The issue of deactivating a live primer has come up a few times with me recently. Most people will tell you one of three things when it comes to removing live primers, and nobody I know has actually tested which is the best method.

The three things that most reloaders say to do are:

1. Place the primed but unloaded cartridge in your gun and pop the primer.

2. Squirt something in the case (usually WD-40 or water) and wait a few minutes. The primer will then be deactivated and can be safely removed.

3. Don't worry about deactivating the primer, just push it out slowly with a decapping die.

Obviously the first method is a guarantee. If the firing pin impacts the primer it will pop the primer and it is a done deal. Unfortunately many people live in neighborhoods where pulling the trigger on a firearm is generally frowned upon (and rightly so). Also, you don't want to pop primers indoors because the gasses they expel include lead vapors. So, although this method is definitely the safest it is also one of the least convenient.

Squirting some water or penetrating oil in the case seems like the next best thing. Kill the primer then push it out, simple right? In theory yes it is, but does it really work?

For the test I took 10 primers each of three different brands (Federal small pistol, CCI small pistol, and Winchester large rifle). I divided each of the groups in half, and placed 5 of each type of the primers in water and penetrating oil respectively (making sure that all primers were saturated, i.e. no air pockets). After 5 minutes, 15 minutes, 30 minutes, 1 hour, and 2 hours I pulled on of each type of primer from the water and the oil and attempted to detonate it (hammer on concrete WHILE WEARING SAFETY GLASSES, will never fail to set off a live primer). I found two things out. First, some brands (CCI especially) are extremely difficult to kill. Every single one of the CCI primers popped at each time interval. Many of the other primers did not go off, except for the water soaked primers at 2hrs. By that time the water had evaporated and the primers went off again. Results were unpredictable at best, and aside from the CCI primers only about half of them fired. The oil did kill more primers than the water did, but only because the oil didn't evaporate. Both killed about the same amount of primers in the shorter time periods.

Although it sounds nice in theory to say just squirt something in the case and push the primer out, it really doesn't work. It could cause some other issues though, especially if you use a penetrating oil. Make sure to clean the case thoroughly of all oil prior to loading the case again (rubbing alcohol wouldn't be out of the question).

The least safe but probably most common method of removing live primers is to not worry about deactivating them and just push them out. I've done this myself more than a few times and never had a primer go off, but I can't stress enough to wear proper safety equipment. Those primers have a surprising amount of force to them. The anvil of the primer could very easily become a projectile with great velocity. The instructor at my NRA Pistol Instructor class had a good friend that chose to remove a live primer and it went off. The anvil went airborne and hit him in the chest. Somehow it got lodged behind a rib and had to be surgically removed! It isn't common for one to go off during removal, but that does not make it any less dangerous. At the very least wear safety glasses for this operation (even if you "deactivated" the primers with oil or water), and it may be beneficial to wear a face shield.

To summarize, the only truly safe way to deactivate a primer is to detonate it, and if you choose to remove a primer before it's gone off please be extremely careful.

Hope this was of interest

Mark