I have around 1000 rounds of Federal .556 and its been stored in a metal military ammo box for some time. Inside these paper boxes.

Federal.jpg

I recently decided to go shoot a little and took a couple boxes out to rotate the ammunition and discovered this.

Federal wtf.jpg

I'm now moving all the ammo into these plastic boxes to try and prevent this from continuing.

Federal 1.jpg

Is this caused by the ammo just aging and not being used, moisture related or low quality loading. Are the remaining rounds safe? I plan to remove the bullets from the bad rounds and dump the powder to dispose of them.