Black spots appearing on my .45 casing? HELP...

[ncmavtgun]

Got a box of PMC Bronze .45 ammo from Turner's about a week ago on sale. I just noticed that several of the casings have little black marks appearing on them. Not sure what they are, but if you scratch them with your finger nails, it comes off. I store them in my closet, which doesn't get hot or moist. The only thing i can think of is that i put a small silica pack in the box for moisture.

Can that have caused this?
Does anyone know what that is?
How to prevent it?

Thanks for any feedback.

[Kid Stanislaus]

Its the creep'n crud. Ship'm to me, I've got a secret formula that'll take it off and prevent reoccurance!

[ripcurlksm]

I'm no expert but I would put a small amount of oil on a rag and give them all a wipe down and maybe try placing them in a new box (different than the box you bought them in).

[rayra]

Keep your greasy biscuit hooks off them in the first place and they'll be fine in the box.
DON'T put oil on your ammo. You'll wind up with a dud.

[ncmavtgun]

Keep your greasy biscuit hooks off them in the first place and they'll be fine in the box.
DON'T put oil on your ammo. You'll wind up with a dud.

I left the ammo alone and didn't touch them since i purchased them.
I only threw in a silica pack.

[gunboat]

If - the cartridge box has a black polyfoam pad in bottom to protect the bullet nose you have found the culprit -- the black poly dissolves getting all over everything --

[ncmavtgun]

If - the cartridge box has a black polyfoam pad in bottom to protect the bullet nose you have found the culprit -- the black poly dissolves getting all over everything --

Nope, i believe it's just black plastic.

[ripcurlksm]

DON'T put oil on your ammo. You'll wind up with a dud.

Not true

http://theboxotruth.com/docs/bot39.htm

Do what you want. Shoot them sooner, than later.

[mecam]

Ammo may be using hotter powder like Titegroup. This happens to all my Titegroup reloads.

[762cavalier]

Do not put oil on your cases. Not because of a misfire, but because when the brass is shot it is supposed to expand to the chamber walls and hold there. If you oil the casing it will not grip the chamber walls and all of the pressure will be forced backward. May cause an bolt failure.

[ripcurlksm]

applying 3 drops to a rag and using it to wipe down 50 bullets can not be all that bad to prevent this mildew from coming back.

[mango salsa]

how long do silica packs last for?

[ripcurlksm]

762 also this is a .45 casing-- the round would be sitting flush against the breech face.. in your post you said it might cause bolt failure, are you referring to another round like 223, etc?

[CSACANNONEER]

Do not put oil on your cases. Not because of a misfire, but because when the brass is shot it is supposed to expand to the chamber walls and hold there. If you oil the casing it will not grip the chamber walls and all of the pressure will be forced backward. May cause an bolt failure.

Funny, I know a few top 50 shooters who wipe every round with WD40 to help the brass flow evenly while fireforming new brass. I guess, these very respected and knowledgable shooters just don't deal with the high pressures that you are refering to? They typically load in excess of 235 grains of VV20N9. If that won't create enough pressure, I'm sure the OP doesn't have anything to worry about with his factory loads.

OP, don't worry about the spots. If you are going to shoot the ammo in the next five years, you won't be able to tell the difference. If you bought 50 rounds for long term storage, ..........well, I'm not sure what to say. So, I'll just say that you don't want to get you oils all over ammo that you don't want to tarnish.