Wheel gun crud rings

[96Briganox]

Hey folks I bought a Ruger GP-100 6" 357Mag a couple of years ago.
Been switching from 357 to 38 Spl and I know it's suppose to leave a crud ring that's not easy to remove.
I'm noticing a ring that looks like it's actually scratched into the chamber. Brass should not harm a steel cylinder like that right? Am I missing something or did any of you see something like this before?
Hope somebody can guide me how to remove or explain.

Thanks.

 

[Claven2]

It's probably just a carbon ring. Try some powder solvent like Hoppes No.9 on a brass or copper brush and scrub it good in each chamber.

If you'd bought a S&W, though.... (just kidding)

 

[96Briganox]

Lol I scrubbed with Hoppes 9 and Hoppes Elite Foam and all kind of other stuff.
Seems like it just doesn't want to come off.

 

[gnmontey]

Well, you can try and scrub that out, but you will be scrubbing for a very long time. It's actually a step in the cylinder

M

 

[stang]

Well, you can try and scrub that out, but you will be scrubbing for a long long time. It's actually a step in cyinder.

M

X2 it's the end of the chamber.

 

[ambishooter]

Flitz

 

[96Briganox]

So it's normal?

 

[stang]

Was made that way. Try chambering .357 empty brass and you'll know.

 

[96Briganox]

Sounds good, thanks for the info guys.

 

[JD3]

Canadian tire get some of this and some elbow grease and will be nice again works very well for me.

 

[Cocked&Locked]

it's just where the chambering ream ended, no worries. Looks plenty clean in there to me

 

[jeffcarr88]

Well, you can try and scrub that out, but you will be scrubbing for a very long time. It's actually a step in the cylinder

M

x 3!!!