Jerry,
My S-code HK (serial # 2122) also does not have either half of a barrer/receiver witness mark...
John D.,...do any of your HK's have witness marks missing ? Mr. Randal Gibson seems to be "silent" on this matter in his book...
I would be worried if the barrel was missing it alone, but could not explain both halves of the marks missing or never being struck...on my pistol.
Regards,
Pete... <img src="graemlins/yltype.gif" border="0" alt="[typing]" />