Question on type II National Match rifle on gunbroker

[Joe W]

I had asked this same question of both Bob Seijas and Dave McClain. Both stated that the NM inscription on the barrel between the rings of the gas cylinder is "engraved" not "stamped". Dave explained as follows : "The stamped NM came first and the folks at SA decided that there was a chance that the bore was being compressed by doing it, it's a fairly deep individual stamp. SA must have air-gaged a few barrels and found some bore discrepancies, it's the only way to check it. They then went to engraving the subsequent NM on barrels that waren't already marked. It's a perfectly logical ascension of NM bbl procedure."
Bob Seijas also said that he has never seen an M1 on which the NM mark was not inscribed on the left side.