I've blued a couple of guns. The first time I did one the same thing happend spots and streaks. The trick too blueing is getting the gun CLEAN, CLEAN, CLEAN Once you've got the gun clean DO NOT TOUCH IT WITH BARE HANDS wear latex gloves. A little heat will also help, when your done blueing get some oil on the gun this will help to keep it from rusting. I use birchwood casey perma blue paste and I have had good luck. One thing to remember is that the best blueing you'll ever get is by someone that has the tanks, but for the hobbyist the perma blue will work.