I've tried this stuff on a couple different rifles now and noticed it leaves a grey residue inside the bores. It won't come off with regular solvent and doesn't want to scrub out with a brush. Anyone else notice it?
I've tried this stuff on a couple different rifles now and noticed it leaves a grey residue inside the bores. It won't come off with regular solvent and doesn't want to scrub out with a brush. Anyone else notice it?



























