Another thing you need to know about Parkerizing is that it by itself will rust just about as fast a bare steel. Parkerizing creates surface porosity which serves as a sponge to absorb oil which gives it it's rust resistance. It's pretty durable stuff, as witnessed by the military's fondness for it.
The end to the process is soaking the part in oil and letting it cure for 24 hrs, then you can wipe off the excess oil. Typically Parkerizing is a charcoal gray, although there are coloring processes for it.
My 03A3 barreled action has a charcoal colored barrel and a greenish action. It should be noted that the barrel has a blasted finish, and the action is smooth. Part of this is because the harder the material is the less the parkerizing solution can penetrate the surface. 03A3 actions are case hardened and the surface is very hard, the barrels are just Cromoly and whereas they may be heattreated they aren't that hard.
I have used the process on my workbench to treat steel parts that were going to be used in a water environment with much success. The key to the whole process is getting the solution above about 165F. That and the harder the part the longer it has to be in the solution.
I have a gun that ws bead blasted and then blued. It has a kind of satin finish to it not as flat as parkerizing.
Like I said above if you are going to get a gun Parkerized make sure the barrel is plugged. The porosity will ruin the barrel for good , you have to rebore to a lartger caliber to fix it.
I guess you could make that Springfield Sporter in .35 Whelen you've always wanted.
Here's a pic of my bead blasted and reblued Bisley
Randy