The U.S. Caliber .30 Carbines - Post WWII

The U.S. Carbine Caliber .30

Post World War II U.S. Army Ordnance Operations

With the end of .30 caliber Carbine production in August 1945, Springfield Armory assumed control of the .30 Caliber Carbine program. Springfield Armory (manufacturers mark SA) manufactured a number of replacement parts and arranged for other parts to be manufactured as needed. Post WWII, Rock Island Arsenal (manufacturers mark RIA) manufactured sears, recoil plates, front sights, and other small parts.

Inspection & Rebuild

As soldiers were slowly cleared to head home, U.S. Army Ordnance began receiving the enormous number of weapons they turned in. These weapons included everything from pistols to anti-tank guns, and more. In every theater of World War II. The weapons were placed in U.S. storage depots all over the world.

If you want to know how to inspect your M1 Carbine, reprints of both editions of this manual are available from various sources (refer to the above link to Books).

Inspecting and upgrading the .30 Caliber Carbines did not happen immediately, or all at once. For many thousands of carbines, it didn't happen at all. In 1945 U.S. Ordnance contracted FN in Belgium to inspect and rebuild various U.S. weapons under the direction of Ordnance personnel. In 1945 Springfield Armory started the first stateside inspection and rebuild of carbines. In the meantime, the need arose to reissue some of the carbines, including those issued to the German Police within the American Occupation Zone in March 1946. Some of these may have been inspected and rebuilt by FN but most were not.

Understanding the Inspection & Rebuild Process

The inspection and rebuild process gained it's name from the manner in which the carbines were inspected and upgraded. U.S. Army Ordnance termed the process an overhaul and issued a manual for the process: TM 9-1276 Cal. .30 Carbines M1, M1A1, M2, M3, U.S. Government Printing Office, 1947, and it's update in 1953. Keep in mind over 6 million carbines had been built, many requiring an overhaul more than once (post WWII, then again post Korean War).

Carbines proceeded down a disassembly line that removed each parts group (i.e. Trigger Housing group, Bolt group, etc) from the carbine one at a time until the barreled receiver was all that was left. Each parts group was then disassembled, with each part placed in a common bin for that particular part. No carbine retained the parts that were on it when it came in the door. After each part was inspected, refinished if necessary, repaired if necessary and possible, everything proceeded down a reassembly line that assembled and inspected each parts group, then the carbine they were assembled onto.

[TM 9-1276 Cal. .30 Carbines M1, M1A1, M2, M3, U.S. Government Printing Office, 1947, pages 28-29]

During the process, parts Ordnance had designated as obsolete were replaced with a later version of the part. These include the following.

  • Barrel Band (replace with band with bayonet lug)
  • Extractor (replace early style with late style)
  • Extractor Plunger (replace early style with late style)
  • Firing Pin (replace early style with late style or modify early style)
  • Hammer
  • Hammer spring (2.125" 22 coils to 2.616" 26.5 coils)
  • Magazine Catch (replace with one that would hold the 30 round magazine)
  • Magazine Catch Retainer Plungers w/ Safety Plunger
  • Operating Slide Stop, Spring, and Pin
  • Rear Sight (replace flip type with adjustable types)
  • Safety (replace push button with rotary)
  • Sear

Parts designed or altered specifically for the M2 were acceptable for use on M1's and M1A1's. They were not mandated replacements for the M1 parts. Some M1's were converted to selective fire and retained their M1 markings.

Marking of Rebuilt Weapons

(TM 9-1276 Cal. .30 Carbines M1, M1A1, M2, M3, U.S. Government Printing Office, 1953, paragraph 24, page 51)

"All carbines rebuilt must be stamped with the initials of the rebuilding establishment in the United States; weapons rebuilt by oversea depot shops are not to be stamped. Stamp the initials identifying the establishment rebuilding a carbine on the left side of the stock between the hand grip and the butt plate. If the weapon is subsequently rebuilt at another establishment, place the new identifying initials directly below those preceding. If the weapon is rebuilt at the same establishment as before, new initials need not be added."

On an operational level the majority of rebuild marks are found on the left side of the stock between the slingwell and trigger housing. However, some were placed above or below the slingwell or on the right side of the buttstock.

Rebuild Markings

AA*    Augusta Arsenal   Augusta, GA
AN    Anniston Arsenal   Anniston, AL
BA    Benicia Arsenal   Benicia, CA
LEAD    Letterkenny Army Depot   Letterkenny, PA
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
TE    Tooele Arsenal   Tooele, UT
   Standard Products (1949)   Port Clinton, OH
U    Underwood Elliott Fisher (circa 1951)   Hartford, CT
P front of handgripindicates rebuild
  • Augusta Arsenal used 2, 3, 4, and 5 letters. Examples include but are not limited to AA, AN, AAL, AAM, AAR, AOY, and AAHO.

  • 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 applied.

Augusta Arsenal rebuild

Twice rebuilt by Augusta Arsenal

Benicia Arsenal rebuild

Letterkenny Army Depot rebuild

Mt Ranier Ordnance Depot rebuild

Raritan Arsenal rebuild

Rock Island Arsenal rebuild

Red River Arsenal rebuild

Tooele Arsenal rebuild, May 1971

Standard Products rebuild

Underwood rebuild

P on front of handgrip indicates rebuild
P on bottom of handgrip used by several original manufacturers as proof mark and not a rebuild mark

Should you have questions, assistance is available on our Discussion Forum.

The Discussion Forum also serves as a reference desk for the more advanced material that could easily overwhelm a website and is often subject to opinions that may vary
due to a lack of original documentation. A number of researchers and authors are present on the forums, helping others and seeking information for various research projects.

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