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Old 09-21-2010, 00:46   #1
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Discoloration on factory 9mm casings

Ok, I don't have an incredible amount of knowledge with ammunition asides from the basics. I was loading my mags and I noticed strange shaped, dark marks all over the majority of the casings. I am using Speer law man 9mm 115gr. TMJ rounds. This is pretty hard to explain so I am going to have pictures to do that for me. My main question is, obviously, what are these marks? why have I never see these types of marks on ANY other of the many brands of ammunition I have used. The only difference I can take into account is that these rounds are TMJ, not the usual FMJ. Could they be treated with something different, which would naturally cause these marks? I really have no idea, I'm guessing they are safe to shoot, but I obviously would want to be sure before I go to the range tmrw afternoon. I've posted pics of the marks on the casings, all I have is my 8 meg camera phone, but I think the marks I am talking about can be seem fairly easily.
Thanks for the help all, I really appreciate it, if someone wants additional pictures of anything that would help them in figuring out what it is, I would be more than happy to take a few more pictures and put them on here. Here are a few bullets where i thought these "marks" could be seen the best. The marks are somewhat resistant to light, which makes them harder to see, so the bullets you will observe you will see "some" of the marks, keep in mind that there are actually many more all over case, its just hard to see them because of the lighting.
Note: I'm guessing there will be quit a few fellows suggesting that the ammo had been loaded in mags many times, of they have cycled through the weapon without being fired. These bullets are STRAIGHT out of the box, 3 of them were loaded in a mag, I left those ones out of the pictures.
again, thanks to all the knowledgable GT's out there that have been able to help me with all of my newb "issues" LOL.

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Last edited by catalyst686; 09-21-2010 at 00:52.. Reason: added information
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Old 09-21-2010, 15:30   #2
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Go to the reloading forum and ask the guys there.
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Old 09-21-2010, 15:34   #3
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Originally Posted by robin303 View Post
Go to the reloading forum and ask the guys there.
Wow this place just isn't what it used to be.
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Old 09-21-2010, 23:15   #4
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It looks like corrosion, but the pics aren't that good. Probably from storage or handling during packaging.
"Given adequate penetration, a larger diameter bullet will have an edge in wounding effectiveness. It will damage a blood vessel the smaller projectile barely misses. The larger permanent cavity may lead to faster blood loss. Although such an edge clearly exists, its significance cannot be quantified".
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Old 09-22-2010, 00:51   #5
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As for your pictures, you are trying to take pictures closer than the minimum focusing distance for your camera. If you notice, the cartridges in the background are in perfect focus. With an 8MP camera, you can enlarge a well focused picture taken another 6 inches from the camera. As to what I assume is corrosion, do they cycle OK? If so, and you only have a box or 2, since they are presumably for the range, I'd say shoot them and forget about it.
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Old 09-22-2010, 03:08   #6
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Catalyst686, there's nothing to worry about, all it is is tarnish on the brass. I've seen this type of tarnish on many brands of ammo, but I've seen it most often on Speer brass. I have no idea what causes it though. My guess is it's probably something like "water spots" caused by not being completely dried off after the cases are washed/cleaned during the mfg process.
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Old 09-22-2010, 15:49   #7
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I see it on factory ammo all the time. It will shoot just fine.

But if you still have reservations, you could mail it to me.

Last edited by Roering; 09-22-2010 at 15:50..
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Old 09-22-2010, 16:03   #8
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Ammo Pox.

Where's Tous when you need the "casing - what sausage goes into" rant?

Just some form of tarnish. Go shoot them and you'll feel better.
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Old 09-22-2010, 20:33   #9
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Thanks for the info, I shot 300 rounds of it at the range today and I had no problems. I wont be worrying about these marks on Lawman ammo anymore.
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