I took my 20C to the range yesterday for some exercise. I blew off about 100 rds of DT 135 gr Nosler and 200 gr hardcast, loads of fun as always. However, later when I was cleaning my gun, I noticed that that the steel surface of the slide around the porting was slighty disfigured and much of the black finish was blown off exposing bare metal. Has anyone else had this happen or is this normal? Do I simply need to send my slide into Glock for refin? If so, how do I go about doing so? Thanks in advance for any suggestions received. ps. Lastly, would it make more sence to simply buy a standard non-ported Glock bbl to avoid this from happening again?