Corrosive Ammunition — How To Protect Your Firearms
Scary stuff — AK-74 after firing corrosive ammo and not being cleaned for a week.
Image courtesy ADCOFirearms.com.
No doubt you’ve heard the term “corrosive” used with respect to ammunition. But what exactly is “corrosive ammunition” (and how does it different from non-corrosive ammo)? What is the chemistry that leads to corrosion, and what cleaning procedures should you follow if you shoot corrosive ammunition? Brownells has come up with answers to these and other questions in a helpful TECH TIP video about corrosive ammo.
In this informative video, Brownells gun tech Steve Ostrem explains the primer-related chemistry that makes some ammo corrosive. The video then reviews suggested cleaning procedures you should follow after you have fired corrosive ammo through any firearms.
What Is “Corrosive” Ammunition?
What makes ammo “corrosive”? Generally speaking, primers are the problem. When corrosive ammunition is fired, the ignited primers leave a residue of corrosive salts. Typically these primers contain potassium chlorate, or sodium petrochlorate which, when burned, change into potassium chloride or sodium chloride. Sodium chloride is also known as common table salt.Potassium chloride and sodium chloride are both very hygroscopic (i.e. they attract water). Because of that, these alkalis are rust generators. When exposed to the hydrogen and oxygen in the air (and moisture) potassium chloride and sodium chloride can form an acid that quickly causes metal rifle parts to rust and pit.
Given a choice, you may wish to avoid corrosive ammo altogether. However, for some types of fire-arms, particularly older military-style rifles, the most affordable ammunition may be corrosive. If you choose to use corrosive ammo, it is important to clean the gun thoroughly after use. After firing, you want to use an element that will neutralize the primer salts. Brownells suggests a water soak (see video above). Alternatively, Windex with ammonia can help neutralize the salts, but that doesn’t finish the job. After the salts have been neutralized and flushed away, basic anti-corrosion protectant (such as Eezox or other gun oil) should be applied to all metal parts.
This video ahows the effects of Corrosive Ammo after one month without cleaning:
To learn more about the proper procedures for cleaning rifles exposed to corrosive ammo, we suggest an article by Paul Markel on Ammoland.com. Markel, host of the popular Student of the Gun TV series, states that: “Windex (with ammonia) is the Corrosive Ammo shooter’s best friend. After you are done shooting your corrosive ammunition for the day, squirt the window cleaner liberally from the chamber down the barrel. Pull the bolt / bolt carrier / op rod if there is one and douse them as well. A couple of old cotton t-shirts will come in handy. A cotton barrel swab is a nice accessory but you can make do with patches. Some folks will rinse all of the ammonia and loosened corrosive salts off with hot water. Others prefer to wipe it all down and let the ammonia evaporate. Either way, once the corrosive salts have been tackled with the window cleaner, it is time for an all-purpose brush (old toothbrush) and some gun oil.” READ Full Article by Paul Markel.
Video Tip from EdLongrange. We welcome reader submissions.Similar Posts:
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Tags: Brownells, Corrosion, Corrosive Ammunitions, Corrosive Primers, Milsurp Ammo
Never actually used Windex, except on windows.
I grew up in Oz, shooting Lee Enfields and Martinis with ammo that was ALL corrosive.
Specifically, it’s the primers, unless you are also shooting black powder, then it is everything.
From the earliest days of the percussion cap (Thank-you Dr. Forsythe), a KEY ingredient in the cap mix was a Chlorate of some sort.. The thing that made the cap “percussion-sensitive” was the Mercuric Fulminate. The Chlorate was added to improve the formation of a big enough flash of sufficient duration to reliably ignite the main black-powder charge., often with the “flash” having to go around a 90 degree bend to get there.
With rim-fire cartridges, the priming mix is located, as the name suggests, around the interior of the rim and is in direct contact with the propellant.
The appearance of the centre-fire cartridge essentially meant going back to a separate “cap”, but this time fitted to a “pocket” in the rear of the case.
All through these developments, the basic primer mix remained much the same, though some manufacturers introduced extremely finely ground black powder into the primer brew, again, to enhance the initial flash, which now had to go through a fairly small hole, or, if Berdan was in charge, two tiny holes, to get to the powder.
Moving into the “smokeless” era, the first thing everybody noticed was that most smokeless propellants are a bit harder to ignite than black powder. However the burn of the main charge runs at MUCH higher temperatures and pressures.
A bit of tinkering produced the flurry of military cartridge and firearm developments that started in the late 1880s. ALL military and “sporting” ammo of this era was primed with “corrosive” primers and until just before WW1, it was also Mercuric based primers all the way.
The mercury is NOT corrosive, however, on firing, the metallic mercury released instantly bonds with the brass case and starts to disrupt the copper-zinc bonds in the metal. This is why fired mercuric-primed cases crack and crumble after either a couple of reloads or just lounging in the “fired brass” box for a couple of months.
The good news is that the corrosive CHLORIDE salts that rust out you barrels are totally water soluble. It was STANDARD practice in many militaries to issue special funnels and provide water-boiling facilities to the troops. Remove the bolt, point the muzzle downwards and, using the nifty funnel, pour BOILING water down the bore. (Without dribbling it into the internal woodwork),
A torrent of nasty-looking liquid will emerge from the muzzle, initially. When it runs clear, run a dry, loose-fitting patch through ONCE, and let the heat absorbed by the barrel drive off any residual water. Sometimes, a bit of “washing soda” (Sodium Carbonate” was added to enhance the cleaning process.
The warm, dry barrel is then lightly oiled and the rifle stored. In “humid” climes, it was standard drill to re-clean the rifles a couple of days later, to be sure, to be sure!. Cleaning materials are cheap. Barrels? Not so much!
Thus were millions of rifles whose diet was EXCLUSIVELY “corrosive”, kept in good order for decades.
‘Emulsion” cleaners like the evil-smelling “Sweets” work well, but repeat cleaning is still a good idea and the caveat about oiling still applies.