I am no firearms expert but I have been a mechanical engineer for 41 years with extensive machine design and structural design experience. Stainless will NOT perform as well as CM in high load / high fatigue / high wear applications. If the design requirements dictate stainless steel then the components must be oversized to gain the same load carrying capability.
In the case of a barrel throat where high temperature abrasion resistance is key stainless steel is not what you want.
In the case of a barrel throat where high temperature abrasion resistance is key stainless steel is not what you want.