|
Maybe this has been beaten to death already, but if I recall (from a report I wrote up 20 years ago, so mebbe not ;-)), chrome forms a passivating film on oxidation (like aluminum), so it is kind of self limiting, ideally.
On the other hand, as others have noted, your barrel itself is probably not chrome, or iron-chrome alloy (like stainless steel), but chrome plated... which is just a thin surface layer of chrome... any defect in this layer, whether in the manufacturing or due to wear/damage, will expose the underlying steel to environment oxygen and water - rust!
Oil, since it is not miscible with water, will help to exclude water from the surface, if you keep/replenish a thin film of it there.
__________________
“Never express yourself more clearly than you are able to think.”
Niels Bohr
|