[KylarStern]

I noticed today when cleaning my XD that there appears to be rust in the rifling of the barrel. I cleaned and cleaned it but couldn't get anything out. How can I remove rust from in the barrel or could this just be major build copper buildup?

 

[ArmyGuy45]

PIC?

And I would use a shirt...

 

[AZXD]

It's probably copper build-up.

Soak it in some good cleaner for a few hours, then give it a good scrubbing.

 

[beretta40xdm]

If you put any copper solvent/cleaner in the barrel and let it sit for 5-10min and the patch comes out with greenish-blue on it chances are it is copper. If not get yourself a hundred rounds and go shootin then oil.