Originally Posted By BuddyChryst:
I was unable to find any of the markings mentioned on my P229.  There are no marking on the underside of the slide.  I changed the grips out to Hogue wrap-around rubberized grips, and can't at the moment find the originals.  Found the owners manual...would've thought they'd be right there with it...

Anyway, as best as I researched quickly, the P229 sold in the US was not assembled in Germany.  So I guess the letter codes do not apply?  The only mark other than the serial # on the barrel I found was a small "P" (no circle) on the side of the protrusion that the guide rod and recoil spring rest.  I did check the mags the pistol shipped with and they were stamped '94.  Was that the first year the P229 was out or was it released in '93?

EDIT:  based on the link on the sigforum (http://sigforum.com/eve/forums/a/tpc/f/430601935/m/467100822) it appears the two letters that start the serial number do, in fact, indicate the year...or at least closely correspond.  The pattern is lost by "AM."  My serial number starts "AD" which appears to be standard for the 1994 year.  Going back means AC is '93, AB is '92 so AA would be '91 (just as .40 cal came out).  But according to this article:
http://averagejoeshandgunreviews.blogspot.com/2008/06/sig-p229-9mm-one-of-most-popular-and.html  
the P229 wasn't released until 1992 and only in .40 cal.