The guy with the answer to the receivers is "Different". Great guy and he KNOWS his stuff.
Send him your numbers and he'll tell you pretty much what time of day it was made and if it was raining.
My 2009 305 is built on a receiver made in 96 , and there is hardly a mark on it.
The appearance of receivers with excessive machining and even welding, in the last year or two is evidence, to me at least, that they are indeed using the stuff that failed QC back in the day.
Bear in mind also that many of the fine builders prefer receivers from rifles pre 07.
As soon as they start making NEW receivers the price is going to really go up, if they make them at all.
We aint seen nothing yet.
Just the opinion of a tired old man whos got to clean out 300 ft of white s@#t to get to work