Hekko everyone.  I was just wondering what everyones opinion was on this.  I know that sronger ammonia-based solvents are not a good idea to leave in chrome lined bores for long periods, but what about #9?  Every so often I do a thorough (read that as anal) cleaning of my bore in my AR and AK and soaking it in Hoppes #9 for a few hours first seems to make the carbon and copper fouling break up easier when it comes to brushing and pushing patches through it.  Can this harm the chrome at all?  Thanks for replies.

I wouldn’t think it would cause any problems.

Hoppe’s #9 is pretty mild.  I’ve heard of folks leaving it overnight in unplated bores with no problems.

(It will mess up nickle, though.)

If it’s a concern, you might want to try Kroil (which is a penetrating oil), instead.

I hoped it would not be harmful.  Does anyone else have any opinions with this?

Im not sure if it would affect the chrome or not since it does contain a small percentage of ammonium oleate(spelling?).
But I dont think I would anyway.
If you want to soak the bore safely use the Kroil as 199 recommends.
Personally I only use Firepower FP-10 to clean for everyday type maintenance.If its allowed to sit in the barrel over night it will float alot of fouling from the bore.Basically works just as the kroil will.
I clean until I get a pretty clean patch and then wet the bore with FP-10.Let it set for a few days and then run another patch dampened with fp-10 down the bore to remove whatever the FP-10 has pulled out.Thats about it for me.
Before shooting I run a dry patch down the bore to remove any remaining oil and suspended fouling,if any.
I only use solvents every once in awhile,primarily for copper removal.
Raymond

It should be ok just make sure it dosn't enter your triger group or any other part of you rifle.