I shot around 400 rounds of The Silver bear 62hps with the nickel cases in two different ARs that I own a month ago at a shoot. Well I went to give them a quick cleaning before this months shoot, and on the bolts of both guns there was a blob of blue carbon. Is this corrosivness? There was a little mark on the one bolt but its really nothing.I cleaned both the guns. Blew them off with gun scrubber and cleaned them with MP7 than wiped them down with clp.The bores looked fine, they arent chrome lined.I know the boxes say Non corrosive. What is the blue crap?Has anyone else had this problem and should I be concerned? All I use this ammo for is shooting steel plates and plinking Thanks for any help!

Haven't seen any BLUE crap on the bolt.  Have seen a couple little flakes of red from the sealant used on the primer.

Yes I have seen the red stuff from the primers. The blue crap was on both of my bolts. They sat around for almost a month.It came off without a problem.