Thread: Rust in the barrel.

Hi guys,
I have a Tikka T3 lite 223 rifle, and have had it now for about 18 months.
It is a stainless steel barrel.
Today I am going shooting so I was mopping out the oil from the barrel before I went.
I noticed an orangy discoloration on the patches when cleaning the barrel.
I had a look with a torch from the crown side and could see some orange on about 4 or 5 groves in the barrel.
I am guessing this is rust, but a little shocked as I oily the barrel after almost every shoot, I have forgot a few times.
The rifle is kept in the gun cabinet always, with a throw away dehumidifier.
And of course it is a stainless steel barrel. I know a stainless can get rust but is much harder.

Anyone got any advise and could this be something else other than rust?

If it is rust what do I do now?