AAM Arsenal Code? M1A1

[hyrax222]

Is this the rebuild code for Augusta Arsenal with the third letter indicating inspector? Or some other. I cannot find this exact stamp in my searches.

[98src]

You are correct in the Augusta Arsenal assumption, but I am not sure if it is known who "M" was.

[Sunray]

Nope. AA doesn't mean Augusta, but the inspector's mark doesn't go with that. AAM is just one of the stamps used by Augusta.
About half way down.
http://www.uscarbinecal30.com/postwar.html

[Tuna]

Yes the AA means Augusta Armory. The M is the letter assigned to the person who inspected the carbine after it was rebuilt.

[JOHN COOK]

Rebuild Markings
Markings Location
AA* Augusta Arsenal Augusta, GA
AN Anniston Arsenal Anniston, AL
BA Benecia Arsenal Benicia, CA
MR Mount Rainier Ordnance Depot Fort Lewis, WA
OG Ogden Arsenal Ogden, UT
RA Raritan Arsenal Edison, NJ
RIA Rock Island Arsenal Rock Island, IL
RRA Red River Arsenal Texarkana, TX
SAA San Antonio Arsenal San Antonio, TX
SA Springfield Armory Springfield, MA

STD
PROD Standard Products (1949) Port Clinton, OH
U Underwood Elliott Fisher (circa 1951) Hartford, CT

P front of handgrip indicates rebuild
Notes:
Augusta Arsenal often used a third letter. Examples include but are not limited to AAL, AAM, AAP, AAR, AAS, and AAU.
FN overhaul program (1945-1946) supervised by U.S. Army Ordnance did not mark carbines, pursuant to a U.S. Army Ordnance directive (above) indicating no facilities outside of the U.S.A. were to place markings indicating they had overhauled U.S. Carbines.
Inspections and refurbishing were also conducted by U.S. Ordnance depots outside the continental U.S., with no rebuild marks.

Copied this .
Thought it might help

john

[Tuna]

The other rebuild center was in Japan done by Howa during the Korean war. The time line for the rebuild program is a bit off in that both Standard Products and Underwood received their contracts in 1948 though 1949. 400,000 carbines were rebuilt during that time frame. Underwood later about 1951 received a contract to make new type 3 round bolts as replacements. These are marked in the original locations with a U and the they all have the hole in the bottom of the bolt which WW2 bolts did not have. These are still found today new in packaging but are not WW2 made so not correct for any period restoration.