I have shot matches with Jerry Miculek on his squad. I can assure you he does not shoot lead bullets during competitive matches. I remember very clearly at the American HandGunner shootoffs in Colorado he was shooting Hornady XTP bullets in his handloads. He won the overall championship one year revolver vs. a semiauto race gun.
Todd Jarrett walked up to me at the USPSA Nationals one year, saw I was shooting lead. He shook his head and said: "You can't see a thing with lead in your gun". I have been at matches with high humidity and no wind where the smoke hung in the air badly.