There are several methods for giving a coat of Copper to the steel. The Most common (Used in Russia–Soviet Union) is to Roll the steel and copper together under pressur, to effectively produce a Bi-(actually Tri) metal strip, before Punching out the cups and drawing the case. THis gives a case which has a copper coat both inside and out…a lot of USSR etc. cases were made with only one (outer) coat of copper; the Extractor cut is then Laquered ( copper cut away, at least for Rimless cases), and the Mouth is sealed with a lacquer as well.
The copper’s main purpose is to facilitate drawing the cases thru dies in manufacture; its anti-corrosion properties are minor ( Coppered cases rust just like other (laquered) steel cases.
The other method is the German “Galvaniziert” method, or electrolytic deposition of copper on the steel ( already used in the 1930s by the German Industry). IN this process, cases are made from steel and then when finished, given a Bath of Copper salts and an electric current , which deposits a thin skin of copper on both outer and inner surfaces of the case, including Extractor groove and Primer Pocket. It is a more energy expensive process than Rolling the steel with copper, and also costs in terms of strategic copper.
That is why the Germans went over to Bonderised & lacquered steel cases in 1940—and why the Czechs went on with this process in the Cold war ( and Russia has returned to it now).
These Chinese ( NIC…Norinco Industries China??) .30-30 cases look like they are “electrolytic coated” as seen by the complete coating of the extractor relief groove in front of the rim.
The coating will be very thin ( as an “anti-rust”) and probably will rub off in couple of passes in a tumbler or thru reloading dies. The “Rolled” copper on USSR cases tends to flake off after Resizing, or exposure to Moisture ( rust “flakes” off the copper from underneath).
Probably was not a viable Project, especially with “Berdan” priming…Boxer may be another matter, but with US shooters being wary of anything “steel” ruining their reloading dies ( another myth), the world’s biggest market would not support such a concept.