Re: Hard chrome
You are likely looking at 6/1,000 of an inch buildup if you want to hard chrome an action. Most actions have room for that, so it's likely possible, but the question is, "Why?".
Chrome if you want a mirror finish. Nothing else will give that to you. Chrome plating tends to not be uniform as the electrical fields attracting the plating are stronger in some areas than others.
If you are looking for weather protection, electroless nickel gives a more uniform coating & is rustproof. Yes, chrome is a harder metal & nickel can scratch, but nickel is the plating of choice for weather protection.
Other choices to ponder for weather protection are any of the chemical based coatings or the baked on enamel paints.
For the ultimate foul-weather hunting rifle, I recommend nickel plating followed by a baked on enamel gun paint.