I have some .223 Rem & 5.56 Nato green tip ammo that I bought in 2013 from two different places. I bought 1k rounds from United Nations Ammo and 1k rounds from Target sports. and have had them in Cardboard and styrofoam ammo boxes which caused them to tarnish, I think. I have read good things about FLITZ but have only used Nu Finish so I decided to do my own test. I ran 1 hundred rounds in the RCBS Vibrator Tumbler with Nu Finish for 5 hours in Walnut Media and also ran 1 hundred rounds in the RCBS Vibrator Tumbler with FLITZ for 5 hours using Corn Cob Media, and compared to two batches, they are exactly the same brightness and both removed the tarnish, in my honest opinion. For the price I paid for FLITZ which was way more than I paid for Nu Finish, I will use Nu Finish when I tumble my brass. All I wanted it to do it remove the tarnish, both products produces the shine and removed the tarnish, so I will just use Nu Finish. I have also used Iosso and Nu Finish was way better than Iosso. Live and learn is what I always say.