I've only shot a couple hundred Blue so far out of my CZ Czechmate Parrot but haven't seen any blue residue in the comp. 115's at just over 1400 fps for reference. I use them in my light .38 short colt loads as well and will be trying some .44 special and 454 casull soon. Overall great bullets, just make sure you flare the case mouth plenty and don't overcrimp.