I never loaded this ammo or really took it out of my safe.


Its Winchester PDX1, 230 grain bonded JHP.

Galvanic reaction due to dissimilar metals. How's the humidity in your safe?

Im not sure. Its a small 10 gun stack on safe with a combo lock. Its packed full. I have about 4000 rounds on the bottom level, 6 rifles on top of the ammo, and on the top shelf sit 5 handguns.

 

Do you recommend that I get a golden rod or something?

Were you, by any chance, eating crackers when you opened the box?  Of course you should use a dehumidifier in your gun safe (especially with a Stack-On safe).  Here's one of the better rods you could use:  

Golden Rod, 12 inch, Dehumidifier Rod  

Took me less than an hour to install one in the bottom of my safe; (Which is where it should be placed.) and, over the years, it's been well worth the money and effort.  (I had to use a high speed drill in order to put a small hole in the side of my safe to  pass the connection wire through.)  After that everything is fully automatic; all ya got 'a do is make certain the plug remains in the wall outlet.  You'll need to use a lot less gun oil, as well.  

As for the stored ammo?  Army ammo cans with gasketed lids are one of the best ways to store ammo for an extended period of time.  (In cardboard is one of the worst!)

I use silica gel (desiccant) and put it in with my ammo and inside my safe.

It's tumbling media. Winchester is well known for this.

Interesting. It wasn't there when I purchased it.

 

Betcha it was and you just didn't notice it. What looks like little grains of sand stuck between the primer and the case don't just magically appear.

Unless it's galvanic corrosion. Then yes, it does just APPEAR

 

I've seen this on new store bought ammo I have always assumed it was polishing media.

THIS. I have seen it before. Nothing to worry about.

If it were the result of galvanic corrosion, you would see some verdigris (green). Also, the primer cup and the case are not dissimilar metals and not really subject to this action.

ETA- OP, take a toothpick and gently drag it through the space where that material has collected. It will likely come off pretty easily and if you can get enough of it together it will have a waxy, gritty (but not abrasive) feel.

Winchester tumbles their better ammo before packaging. It is media and does not hurt anything.

Yup. Tumbling media. Seen this on Winchester ammunition since the 1980s. Even seen it stuck to the red primer sealant. Nothing to worry about..

1DD

yup polishing media, normal