While I have been reloading for decades now, I have run into something that I've never experienced before. I am new to this forum but was hoping someone could help me out here. About a year ago, a friend gave me a 5 gallon bucket full of .40 S&W brass for reloading. I bought him lunch for same (quite a deal huh). Today I removed the lid from the bucket for the first time and all of the brass had turned black, solid black. I ran some through my brass polisher with no luck reclaiming the brass color. I was hoping someone could tell me if this brass is safe for reloading. Thanks in advance for any info.