^^^ I've looked down many bores and can honestly say that I haven't personally identified copper fouling bad enough to see with a flashlight. I have however cleaned out many bores that were suspect and brougth them back to standard using amonia bearing solvents that turned the patches blue. My feeling is that if you can literally see it with a flashlight, shooting....no spraying patterns would be your initial indicator.
On another side note, this KG stuff claims to not contain ammonia, neither does Wipeout. We all know how effectively amonia attacks copper, but hey, I'll give anything a try at least once. We all know how copper fouling will deteriorate accuracy in a jiffy.
