[Tegboarder]

To clarify on the lower receiver stamping I am not saying that the round you fire will affect the lower receiver; but if you are looking at a complete factory weapon with a lower and upper that were paired together, then the stamp on the magazine well is referring to the chamber on the upper. I wasn't aware of a stamp on the underside of the barrel. That being the case it's a better place to check that you are using the right ammo considering you are not always going to be looking at an upper and a lower that were made together.

TR, I finished the course back in May. I'll update the profile right now.