Who else here has cleaned this stuff out of their gun thinking it was copper residue when they first bought their Glock ? Did they just start doing this ? Last Glock I bought in the mid 90's didn't have this crap in it ? After reading the manual I noticed you are suppose to keep this stuff in there. After one day at the range though it's gonna get washed out anyway when you clean it, I don't understand ?? It's gotta be something relatively new ?