I use Chore Boy myself and it works very well. However, just my thoughts regarding steel wool...it is likely much softer than the steel in a gun barrel. Conceivably, damage could probably occur if overdone, but it might require a lot of effort. It doesn't seem like regular, judicious use would harm a bore, but that's using conventional wisdom on my part and may be wrong.

Perhaps there are some real experts on here that know the facts.