This is the only marking that I've found. Is it U.S. or foreign? Is there a marking list on the site? I'm new. I have a picture just not sure how to post it. The marking is located on the left side of the stock just forward of the sling well and is NOP with an M inside of an inverted u followed by the number 62. Any help would be appreciated especially on how to post a picture.
Email me the picture and I'll put it up for you. I've had similar stock markings and my conclusion was that it most likely was Naval Ordinance Plant Macon. I believe mine said "61". don't know about the inverted "U" - maybe an inspector's mark.
Here is a link to the photo. The upside down U is an Underwood re-build mark. One source gives circa 1951 as the date. And then the NOPM that I have seen. Interesting, the two overlapping marks appear as one stamp.
Yup but the Underwood rebuild stamp dates to 1948 and 1949 when they had the rebuild contract along with Standard Products. 400,000 carbines were rebuilt in that time frame. It also helped Underwood get a contract for more type 4 bolts. These can still be found today unissued. They will have the oil hole on the bottom. It's an easy way to tell and date them.