Oh testing, me likee!
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Oh testing, me likee!
Test group 2 results:
Before removal from the water. As expected the corrosion is of the same nature as Test Group 1, only more severe.
http://imageshack.us/a/img705/1945/dscf6670e.jpg
http://imageshack.us/a/img844/9397/dscf6671d.jpg
Upon removal, an odd finding was discovered. On the polymer coated rounds, a "crust" of sorts has formed on the exterior of the casing. I do not believe this to be deposits from the water, as it only appears on the polymer coated rounds. It would scratch off with a finger nail but wouldn't wipe off with a paper towel. The "worst" side of each round is shown in the photo.
http://imageshack.us/a/img35/5548/dscf6673j.jpg
The samples from Group 10: Not ready for firing, this was taken to show progress. As can be seen the laquer coated cases are standing up much better to the effects of humidity.
http://imageshack.us/a/img812/5876/dscf6677b.jpg
The rounds placed in natural conditions appear unaffected to date. Nothing to report.
All of the rounds from Test Group 2 chambered, fired, and ejected normally. 1 month of complete underwater submersion did not cause any failures. Both ammunition types move on to the next phase.
awesome test! i found an old pmag that had been out in the yard full of tula for well over a year....jammed it in the ar and rattled it off like it was nothin
I will keep a eye on this
Can you post pics of your groupings?
Um... unfortunately no. I'm shooting at whatever I can dig out of the floorboard of my car, or just into a dirt hill in the prairie. It's all been fired off at night, cause that's when I'm out running around. Plus it's all been fired out of my Draco SBR so it wouldn't really be of any conclusive value anyway. Sorry.
Awesome testing. Thanks for sharing !
great posting. Thanks.
TEST GROUP 3: 2 Months of water submersion
Again, significant evidence of corrosion
http://imageshack.us/a/img9/593/dscf6724d.jpg
http://imageshack.us/a/img534/6102/dscf6725k.jpg
Polymer cases show far more severe corrosion. The "crust" that had formed at one month is now absent though the cases now have a rough texture due to rust. The laquer coated cases are beginning to show discoloration but still feel smooth to the touch.
http://imageshack.us/a/img802/6752/dscf6731r.jpg
http://imageshack.us/a/img811/7660/dscf6728.jpg
This photo shows the rough surface of the casing on the polymer coated rounds
http://imageshack.us/a/img560/4797/dscf6732w.jpg
All rounds from TEST GROUP 3 chambered, fired and ejected normally, no failures.
TEST GROUP 6: 2 months exposure to natural elements
No significant evidence of corrosion, only a minor blemish on a few of the rounds. The rounds had been snowed on a few times and subjected to freezing temps on numerous occasions.
http://imageshack.us/a/img18/4978/dscf6730m.jpg
All rounds from TEST GROUP 6 chambered, fired and ejected normally, no failures.
Status report on the the "high humidity" test groups. Not ready to be fired, this is just to show progress.
http://imageshack.us/a/img812/5876/dscf6677b.jpg
So, does it look like the polymer coating dissolved in the water or did it separate from the steel case? I'm interested in this as some polymers will eventually break down in polar solutions, but most wont. I'm wondering if they cut corners on the polymer coating and went with a cheap coating not intended for long term submersion. The other possibility is the polymer didn't fully seal and so is letting water eventually penetrate between the coating and the steel and the oxidation of the steel caused the polymer to peel off.
Just curious. I would suspect you would find the polymer coating in flaked off pieces if the latter is true.