Flirting with Failure: Extreme Corrosion Ammunition Testing

Now a few words from Mad Duo Merrill, whose love of interesting hats is second only to his willingness to shoot just about anything that will go bang. Mad Duo

Flirting with Failure: Extreme Corrosion Ammunition Testing

Dave Merrill

A few weeks back I found something interesting in the bed liner of my truck: some loose 7.62×39 ammo. To say that it was in bad condition would be an understatement; it looked like it was covered in some science fiction living Soviet moss. Even the projectile was covered in rust, WTF? As evidenced by NASA’s Curiosity rover, the surface of Mars is less orange than this ammunition.

rounds

Overseas, found weapons caches are often evaluated in order to get an idea of the competency level of whoever placed it. A well packed, lubricated, and sealed cache shows an educational of at least grade school. This ammunition, exposed to the elements for literally years, falls someplace between, ‘dumbass kids’ and ‘ballsack stupid’.

Initial inspections lead me to believe that this was once 154gr soft point 7.62×39. A quick once over with a wire brush confirmed this to be the case.

Of course, I gotta try to shoot it.

At this point it should probably mentioned that this shouldn’t be tried at home. The risk of an overpressure event is fairly high (assuming ignition can be achieved)–ruptured casings, popped primers, squib rounds and more. When pressure goes where it isn’t supposed to, not only can your test rig be destroyed but your eyes and fingers along with it.

After cleaning a few rounds I wanted to see if these would even be viable. One round was selected, the projectile pulled and the powder set aside. The base of the projectile was clean (that says something about the thick goop that’s used for sealing), the primer popped, and the powder burned. All of this points to [possibly] functional ammunition.

compare

Propper_Breach_300x100

Next step was to find a test rig. No, I didn’t want to just go shove this into an Arsenal or Clayco and let it rip (remember that part about the dangers of overpressure?). After rummaging around in the back of a safe I found it: The. Perfect. Test. Subject.

As you can see from the blueprints, it was manufactured to exacting specifications. Never mind that it doesn’t have a front sight or hand guards, that the top cover has a slot in it for a non-existent left handed bolt carrier, or that the rivets appear to have been done by a six year old. None of that matters in this case. Built from junk parts? Check. Short barrel that meant a squib would be more likely to leave the barrel? Check. Sixty dollars invested more than a decade ago? Triple Check.

test_rig

With the ammunition cleaned and an expendable firearm that accepts the caliber found I fabbed a precise scientific test rig: A lead sled, some barrel clamps so the front end stays in place, and a loooong piece of 550 cord. Range time!

Testing parameters:

Pistol was setup on collapsible table, in lead sled, close to and pointing at a large berm.

Though a ten round magazine was inserted, it served only as a guide.

Only one round in at a time to reduce secondary explosions in case of an overpressure event.

550 cord was looped through the trigger to act as a remote firing device.

3_cleaned

Function:

The ammo worked! (Kinda). Simple chambering was hard to accomplish. Even with all of the obvious corrosion cleaned off it sometimes took a hammer to seat the round. Not good, not good at all. Once again, don’t do this!  While it allowed the ammunition to be tested, it also increased the chance of an explosion. Flirting with disaster with live ammunition is almost never warranted. Extraction simply did not happen without the aid of a hammer and sometimes a knife. Looking at the video, the bolt carrier moves back maybe a quarter of an inch before completely seizing up.

At one point in time the small collapsible table used to hold the rig was physically knocked over by the muzzle blast. While this was immediately corrected by placing some weight on the base of the table, it further demonstrated that only having a single round in the rig at a time was a good decision for safety purposes.

No target was placed in front of the test rig so how the projectiles flew could not be evaluated.

Inspection of the spent casings showed cracks in the case neck, a classic sign of overpressure. Enough to blow up the gun? Not in this case. Had testing continued beyond the half-dozen futzed rounds available it may have.

spent

Lessons learned:

While Russian casings leave much much to be desired in regards to environmental fouling, the sealant used on the neck and primer managed to keep the powder dry and primer functional even over the course of years.

Never shoot found ammunition.

I really should clean out my truck more often.

-DFM


Mad Duo, Breach-Bang& CLEAR!

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About the Author: A combat veteran of the United States Marine Corps, Dave “Mad Duo Merrill” is a former urban warfare and foreign weapons instructor for Coalition fighting men. An occasional competitive shooter, he has a strange Kalashnikov fetish the rest of the minions try to ignore. Merrill, who has superb taste in hats, has been published in a number of places, the most awesome of which is, of course, here at Breach-Bang-Clear. He loves tacos, is kind of a dick and married way, way above his pay grade. You can contact him at Merrill(at)BreachBangClear.com and follow him on Instagram here (@dave_fm).

DFM

Emeritus Dave Merrill wrote for Breach-Bang-Clear from late 2013 until early 2017, including a year as its Managing Editor. He departed our ranks in May of 2017 to accept a well-deserved position as social media manager for RECOIL Magazine. He is a combat veteran of the Marine Corps who describes himself as a "...former urban warfare and foreign weapons instructor for Coalition fighting men." Merrill's articles are well worth the time it takes to read them - there's a lot of knowledge tucked away in that skull.


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2 thoughts on “Flirting with Failure: Extreme Corrosion Ammunition Testing

  • July 2, 2014 at 12:24 pm
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    “Inspection of the spent casings showed cracks in the case neck, a classic sign of overpressure. “

    Isn’t it more likely that the case necks cracked from corrosion and brittleness rather than overpressure? The primers- at least from that picture- look fine and do not exhibit firing pin cratering or backing out that would indicate overpressure.

    Thanks for performing this valuable research. Knowing is half the battle. The other half is not shooting heavily corroded ammo. Cheers!

    Reply
  • July 1, 2014 at 3:55 pm
    Permalink

    People hand me ammo found on the range which they think I’m going to use. They’re nuts. I remember a remark I heard on NPR 30 years ago about mushroom collection. She end the presentation with “Don’t poison yourself over a 39 cents can of mushrooms.” The same applies to found and corroded ammo.

    Rotten Lead? See it up close at shameless plug: http://tactical-talk.blogspot.com/2014/03/so-what-is-it.html

    Reply

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