Agree with the others about not using Frog Lube. I highly recommend Weapon Shield. Bill
Weapon Shield for total gun care.
Ya, froglube gunks up...
Slip2000EWL is good stuff.
I use Weapon Shield since it came out, always performs well!
As a precaution I always wrap my aluminum cleaning rods with Black Electrical Tape to avoid any damage to the bore. Bout ready to try Nylon rods if I can find them.
Try Dewy fiberglass rods
You cannot make peace with those who demand not only your economic submission, but your intellectual and spiritual surrender as well.
Looks like burned on (not in) oil residue. Go out to the garage (so the wife does not complain) and soak that barrel overnight in Hoppes or CLP Break Free (what I use). Brass brush the hell out of it back and forth about 100 times and it will loosen up. Follow up with Hoppes or CLP on a clean cotton patch until it shines. Don't forget to clean the Barrel tongue too.
Everyone is right about Frog Lube. I used it once...never again (took hours to de-gunk the receiver)...live and learn. Rem oil is my favorite. Lightly oil the outside of the barrel and barrel block during regular cleaning. NEVER oil the inside of the barrel unless you are putting up the firearm in storage for more than month. If you do, just lightly oil a patch, run it through 2-3 times and leave the end of the patch sticking out one side of the barrel. That way you will remember to RE-CLEAN the barrel with Hoppes or CLP before going to the range.
+1 on Weapon Shield. It's the only thing that's ever touched my P30 and P30SK.
Guess the electrical tape thing works, but I just pick up a long plastic soda straw from my favorite fast food joint, cut it to length, and slip it over the rod. Easier to change than having to unwind all that tape.