Can parkerization rust?
Yes. Unless you properly clean off the warehouse packing product, cosmoline and completely oil the parkerization, rust can begin to form in a very short amount of time. When first receiving and cleaning the parkerized firearm, literally spray the finish (with a great product like RemOil) until it drips wet, go have a cup of coffee, then return and towel dry. This gives the lubricant time to fill the pores of the parkerization.