Rust in Bore Help 1903 A3 !
I am worried my Remington 1903 A3 has a strong Rifeling but I shined a flashlight down the muzzel and It has what looks like rust in the grooves near the muzzel. I have not fired corrosive amunition and It had an oiled patch run through it before storage. I ran a patch through the bore and It came out black, so I scrubbed It out with Shooters Choice, patched it till the patches came out clean, fired it three times. (it grouped tight) re cleaned it, shined the flashlight again and Its still there. What should I do ?