As I said before, the Chinese could produce nicer receivers, and have. They are building to the importer's price point.
The way it works is a Canadian company - let's call them North Sylva - asks the Chinese to supply a M14S rifle. Jianshe (or other arms plant) opens their catalogue - probably on a chinese made apple tablet - and says their standard offering costs (pick a value). A conversation ensues:
NS: "gee, that is more than last time".
Jianshe: "ok, what price point make you go happy sunshine?"
NS: "as cheap as last time, or ideally even cheaper".
Jianshe: "We make super-fantastic rifle, new MIM technology go cheaper"
NS: "We are all about cheaper. Give us the cheapest rifle you can that still uses the same receiver. We know we can't cheap out on the receiver and still sell these things."
Jianshe: "ok big boss man. We make super fantastic M14 with MIM, maybe some 3d Printer mechanic too".
Phone hangs up.
Jianshe: "Stupid capitalist dog. How he not know rifle break after 250 bullet hose?"