Thanks for you response and thoughts!
I just received my SR 40 C by FedEx this morning. Ruger factory in Prescott Arizona replaced Extractor, magazine disconnect, slide stop assembly, Stryker assembly, stryker blocker, trigger assembly, trigger bar lift spring, trigger bar reset, ejector and fire control housing,
After repair , Pistol was function fire with 27 rounds of Black Hills 115 grain full metal jacket and 18 rounds of Lawman 165 grain without malfunction.
This weapon was made in first year of production in 2011 and perhaps they thought it best to update with newer design parts.
I am not comfortable with dirty striker channel theory since it went from strong primer dents to not even a mark on the primers.
Ruger didn't even charge for shipping