Chinese guns are built to sell at a relatively cheap price point. Labor costs notwithstanding, something has to give to do that - whether that is improper, poor, or non-existent hardening, poor quality materials to begin with, shoddy workmanship or assembly procedures, or any of a myriad of other reasons, cheap guns are cheap because they were made that way to sell.
Maybe you'll get a decent one, maybe not - the old adage about the cheapest tool in the tool box is also the most expensive, comes to mind