Chamber Obstruction in 1898 Krag Rifle

[madsenshooter]

Pinkish, probably red bullet lube. When I first started shooting cast at low velocities and pressures, I noticed lube blowing back on cases and it built up after awhile, leaving a discernible mark that grew further down the case as I shot more till it was about halfway down. I was using black lube at that time. I got it out with a chamber reamer. At higher pressures there's no blowback onto the case, except the neck.