That picture is about half way down the barrel and most of the barrel looks the same way. Its not just the bottom of the barrel. Would any type of cleaning help ?If that’s the bottom of the barrel they all will look like that after a while. Even a aftermarket barrel. Nature of the rimfire ammo
mostly match ammo with some CCI sdThis stuff worked to clean a severely lead fouled barrel.
View attachment 1297845
What ammo are you shooting?
