The U.S. Caliber .30 Carbines - Serial Numbers

The U.S. Carbine Caliber .30

U.S. Army Ordnance
Serial Number Assignments

Serial Number Tables

Models M1, M1A1, M2
 By Prime ContractorTable A
 Numerical OrderTable B
 Subcontracted Receivers Table C
 Leftover Receivers used by WinchesterTable D
 Transferred ReceiversTable E
 Duplicated Serial NumbersTable F
 Irwin-Pedersen, Grand Rapids, & SaginawTable G
 Inland Mfg - Engineering & Presentation GiftsTable H
 8 Million Serial NumbersTable I
Model T3  T3
Model T4  T4

Understanding Serial Numbers - Understanding Dates of Manufacture

Dating a carbine by its serial number alone is difficult and not always accurate given the circumstances inherent with manufacturing and the logistics situation during the time the carbines were manufactured. Some people estimate a carbine's date of manufacture by adding the quantities manufactured month to month to the assigned serial number blocks. This is not an accurate means of estimating the date the carbine was finally assembled or when it passed its final inspection.

Serial number blocks were assigned by the Ordnance Department on an as needed basis, generally in response to the awarding of a contract to a given manufacturer. Think of each serial number block as a separate contract. Contracts had a completion date but there was no requirement for completing one contract before starting another. There was no requirement as to using the serial numbers in order.

A few manufacturers used some serial number blocks out of order. Some of these blocks were split up and used before or after other blocks. Some manufacturers used more than one block in the same time frame.

A few of the manufacturers used subcontractors to manufacture their receivers. One manufacturer separated out smaller blocks of serial numbers for use by subcontractors who would use these serial numbers concurrent to receivers being made by the prime contractor and/or other subcontractors assigned lower or higher serial number blocks.

The serial number was placed on the carbine receiver during the manufacturing process of the receiver, not when the carbine was finally assembled. The decision for which receivers would be used for the U.S. Carbine Models M1 or M1A1, and some of the M2's, were made well after the receiver was completed as all of these models used the same receiver.

Serial numbered receivers that failed to pass inspection were set aside as rejects if the defect(s) could not be brought up to minimum standards. As solutions to old problems were learned, some of the same receivers were brought back online and completed (i.e. Inland receivers initially rejected because of an off spec deep hole drilled for the recoil spring and guide, later recovered and altered to use a detachable main spring housing). If a receiver was scrapped and not used, its serial number may or may not have been reused.

No documentation from Ordnance, or any of the prime contractors, has been found that indicates the date and serial number of carbines as they were assembled or when they passed final inspection. Given the high volume of production, receivers were generally assembled as part of a carbine within a few months after the receiver was serial numbered.

Barrels were a critical component in the production lines. If inventory ran out it could shut down production. Four of the prime contractors did not have the ability to manufacture barrels. The ebb and flow of mass production created parts surpluses and shortages for all the prime contractors, barrels included. Shortages were common until Ordnance arranged for additional barrel manufacturers.

During the first half of production the barrels were often mounted on a receiver within 1-2 months of when the barrel was made. If a receiver has its original barrel and the barrel includes a date, it may provide a general idea of when the barrel was attached to the receiver.

As time goes on more and more carbines are having parts replaced. Parts wear out, carbines are disassembled for the sale of the parts individually. Carbines have been, and still are, rebuilt from spare parts. Many people have reconstructed many carbines with what they believe should have been on the carbine when it left the factory.

U.S. Caliber .30 Carbine
Models M1, M1A1 and M2


Prime Contractor

Prime ContractorStartEnd
National Postal Meter1,450,0001,549,999
4,075,0104,432,099 Commercial Controls (1)001239
Quality Hardware1,550,0001,662,519
Saginaw (S.G.)3,250,0203,651,519
Saginaw (S'G')/Irwin-Pedersen1,762,5201,875,039
Standard Products1,982,5202,352,519



Numerical Order

StartEnd Prime ContractorNotes
15 InlandToolroom Models (2)
610 WinchesterToolroom Models (2)
1199 InlandEngineering (3) & Experimental (4)
100999,999 Inland(see Tables C, E, F)
1,000,0001,349,999 Winchester 
1,350,0001,449,999 Underwood 
1,450,0001,549,999 National Postal Meter 
1,550,0001,662,519 Quality Hardware 
1,662,5201,762,519 Rock-Ola 
1,762,5201,875,039 Irwin-Pedersen/Saginaw (S'G')(see Table G)
1,875,0401,937,519 Quality Hardware 
1,937,5201,982,519 National Postal Meter 
1,982,5202,352,519 Standard Products 
2,352,5202,912,519 Underwood(see Tables C, D, E)
2,912,5203,212,519 Inland(see Table C)
3,212,5203,250,019 Irwin-Pedersen/Saginaw (S'G')(see Table G)
3,250,0203,651,519 Saginaw (S.G.)(see Table G)
3,651,5204,009,999 IBM(see Tables C, E, F)
4,010,0004,074,999 Underwood 
4,075,0004,075,009 WinchesterWinchester gift guns
4,075,0104,432,099 National Postal Meter(see Table C)
4,432,1004,532,099 Quality Hardware (UN-QUALITY)(see Table C)
4,532,1004,632,099 Rock-Ola 
4,632,1004,879,525 Quality Hardware 
4,879,5265,549,821 Inland 
5,549,8225,549,921 not assigned 
5,549,9225,834,618 Winchester(see Tables D, F)
5,834,6196,071,188 Saginaw (S.G.) 
6,071,1896,099,688 Rock-Ola 
6,099,6896,199,688 Underwood 
6,199,6896,219,688 Rock-Ola 
6,219,6896,449,883 Inland 
6,449,8846,629,883 Winchester 
6,629,8847,234,883 InlandModel M1 & Model M2
7,234,8847,369,660 WinchesterModel M1 & Model M2
7,369,6618,069,661 InlandModel M2
higher s/n's (post WWII)(see Table I)

(1) leftover carbines offered to Ordnance after a company name change and completion of the NPM contract
(2) Toolroom Models: Pre-production carbines to test and finalize drawings for mass production
(3) Engineering Models: Pilot models made from Engineering Drawings
(4) Experimental Models: alternate designs experimenting with ways to reduce the time and cost of production


Tables   C - F

Documents found in the past have identified several prime contractors who assigned subsets of their serial numbers to their subcontractor(s). Data collected over the years has sometimes conflicted with the information in these documents. There are a variety of reasons things may have been changed or simply ignored.

Rather than assume the documents were followed to the letter, the serial numbers in tables C-F are presented with the lowest and highest reported to date. We would like to encourage you to share information you may have that will help reconstruct what was actually done versus planned. If you choose to do so please contact us using the forum.


Subcontracted Receivers

(also see Table E)

LowestHighestPrime ContractorCodeSubcontractorNotes
700,126 709,449     Inland SI Saginaw S.G., Saginaw, MI(also see Table E)
707,298 938,380     Inland SG Saginaw S.G., Saginaw, MI(also see Table E)
940,600X 950,919X     Inland SG Saginaw S.G., Saginaw, MI(also see Table F)
2,352,521 2,400,080     Underwood T Intertype Corp.(also see Table D)
2,452,638 2,491,453     Underwood W Universal Windings (also see Table D)
2,572,558 2,601,955     Underwood S United Shoe Machine  
2,625,041 2,682,871     Underwood B Singer Mfg (also see Table D)
3,152,529 3,199,190     Inland SG Saginaw S.G., Saginaw, MI  
3,835,477 3,907,689     IBM AO Auto-Ordnance s/n's intermixed w/IBM s/n's (also see Table E & F)
4,325,227 4,387,735     National Postal Peter U Union Switch & Signal the U is different than Underwood U
4,432,255 4,466,225     Quality Hardware UN-QUALITYUnion Switch & Signal  



Leftover Receivers used by Winchester

Underwood had receivers in various stages of completion left over when their contract ended. These receivers were purchased by Winchester.
What followed was not always consistent and sometimes varied. The information that follows has been reconstructed from the data collected so far. It is not unusual
to find a receiver that doesn't fit these criteria. The focus at Winchester was meeting production quotas during a time of high demand.
    - Underwood receivers that had not yet been hardened:
      Winchester removed the Underwood name and serial number, then replaced them with the Winchester name and serial number.
    - Receivers that retained the Underwood name:
      Winchester sometimes lined out the Underwood name, sometimes not.
    Winchester added the letters W A or A W to the bevel of the receiver.
      - If the receiver had an Underwood subcontractor code, the subtractor code was left in place between the W A or A W.
      - One or both of the letters of the W A or A W code may be difficult to see. Some have been reported with only one of the
         two letters or in combination with an Underwood subcontractor code.
      - The significance of the letter A is unclear.

LowestHighest  InfoCode
1,244,6971,290,339 Underwood name removed, Winchester name & s/nA W
2,38x,xxx2,404,928 Underwood name not lined out, Underwood s/nWTA
2,485,1252,491,867 Underwood name not lined out, Underwood s/nWwA
5,759,1xx5,801,924 Winchester name, Winchester s/nT
5,814,7985,820,062 Underwood name removed, Winchester name & s/n A W
6,461,4796,482,225 Underwood name lined out, Winchester s/nA W, W A
6,473,811 ? Underwood name lined out, Winchester s/nNo Code
6,497,1536,614,551 Underwood name lined out, Winchester s/nB, BA, ABW, BW



Transferred Receivers

Ordnance required the name of the prime contractor to be defaced by a single narrow horizontal line. The
identification mark of the receiving facility was to be added at the rear of the serial number.

Serial numbered receivers transferred were not restricted to a certain block of serial numbers. Some were sequential but many were not.

LowestHighest  InfoCode
126,794 127,006  Inland s/n'd receivers sent to National Postal MeterN
438,xxx590,828 Inland s/n'd receivers sent to RockolaRockola
496,xxx634,161 Inland s/n'd receivers sent to UnderwoodU
702,607 ?  Inland s/n'd receivers from SI subcontract sent to UnderwoodU
724,318751,395 Inland s/n'd receivers from SG subcontract sent to UnderwoodU
1,765,7611,769,771 Irwin Pedersen s/n'd receivers sent to UnderwoodU
2,743,2862,770,326 Underwood s/n'd receivers sent to National Postal MeterN
3,842,1773,846,371 IBM s/n'd receivers from AO subcontract sent to National Postal MeterN
4,049,244 ?  Underwood s/n'd receivers sent to National Postal MeterN



Serial Numbers Duplicated

(including use of X Suffix)

Prime contractors and/or subcontractors sometimes ran over their assigned serial number block and into a block assigned to
another prime contractor and/or subcontractor, creating duplicate serial numbers. Ordnance dealt with this by directing
an X be added after the serial number of the receiver that exceeded the assigned block if duplicates were found.

There is insufficient data to determine if every serial number between the lows and highs was duplicated or if it was random.
It is assumed some were sequential but possibly not all. More data submissions are needed to help determine any patterns.

Lowest Highest  Manufacturer Code Details
940,600X     950,919X       Saginaw subcontract for Inland X at end of s/n Duplication of Inland s/n's
3,651,550        3,651,898          SG ? Duplication of IBM s/n's
3,835,477-X    3,907,689-X      IBM no identifying markings IBM duplicated some of s/n's they assigned to AO
4,800,004        4,801,447          Quality Hardware X below s/n Possible duplication of their own s/n's
5,550,040-X    5,550,285-X      Inland -X below s/n Overrun into unassigned s/n block & Winchester s/n's
5,550,148        5,812,437          Winchester D below s/n Significance unknown
5,557,074-X    5,557,996-X      Inland -X below s/n Machine error duplicating Winchester s/n's



Irwin-Pedersen, Grand Rapids, & Saginaw

None of the carbines produced by Irwin-Pedersen (IP) were accepted by Ordnance. Saginaw Steering Gear in nearby Saginaw, MI was already engaged in the preparation for the manufacture of carbines along with providing subcontracted receivers for Inland. The Irwin-Pedersen contracts were terminated by Ordnance. An Ordnance supplement to the Saginaw Steering Gear (SG) contract turned over carbine production at the Grand Rapids facility (S'G') to Saginaw Steering Gear.

Irwin-Pedersen Numbers Reassigned to Saginaw at Grand Rapids

Grand Rapids manufactured their own receivers as well as using viable IP marked and serialized receivers they had acquired in the takeover. Serial numbers IP had not yet used were used by S'G'. As were serial numbers from IP receivers that were scrapped

Serial Number RangeS/N Block Reassigned toMarkings on ReceiversNotes
1,762,520 1,875,039 Saginaw Grand Rapids Irwin-Pedersen or Saginaw S'G'names are intermixed
3,212,520 3,250,019 Saginaw Grand Rapids Irwin-Pedersen or Saginaw S'G'names are intermixed

Saginaw Receivers with SG Subcontractor Markings

Receivers produced at the Saginaw plant under subcontract to Inland initially had the SI receiver code on the left side of the receiver below the wood line. The receiver code was soon changed to SG. Receivers with the SG receiver code were intended for use by Inland though they were also used by Saginaw. The serial numbers and manufacturer names identify who actually used the receiver.

Serial Number RangeS/N Block Assigned toMarkings on ReceiversNotes
3,250,020 3,651,519 Saginaw SGSG on left side of some receivers, not all

Saginaw SG Markings on Receivers with Grand Rapids Serial Numbers

Among the last 1000 serial numbers of a block assigned to the Grand Rapids plant, receivers manufactured in Saginaw with SG markings have been reported mixed in with S'G' marked receivers manufactured in Grand Rapids.

Serial Number RangeS/N Block Assigned toMarkings on ReceiversNotes
3,249,020 3,250,019 Grand Rapids S'G', some SGpossibly as many as 1000 SG receivers

SG and S'G' Mix of Receivers and Serial Numbers

The data submitted for this serial number range is insufficient to reconstruct what was done by which of the two facilities with each others receivers. The data on these receivers, serial numbers, and prime contractor names is an ongoing research project that needs your help.

Serial Number RangeS/N Block Assigned to
3,541,000 3,651,519Saginaw

Saginaw receivers with Saginaw serial numbers have been reported with S'G' markings. At least one document has been found that indicates Saginaw received Ordnance authorization to sent an unknown quantity of receivers to Grand Rapids. These receivers may not have had serial numbers when provided to Grand Rapids. The Grand Rapids facility stopped carbine production on 01 Jan 1944 but continued to make receivers and trigger housings which were sent to the Saginaw Plant for assembly.

Assistance Request

If you own one of these carbines and would like to assist with the
reconstruction of this history, we have a short survey on our forum (with instructions)
for you to submit by CLICKING HERE.


Inland Manufacturing
Engineering & Presentation Gift Serial Numbers

(not government issue)

Letter prefixes X through XD were initially allocated by Inland for carbines intended for internal use only. The letters were followed by numbers (i.e. XA27, XA62, XD14). XA through XD was assigned for use by their Engineering Section on carbines built for testing and evaluation by their engineers. The quantity of carbines used by their Engineering Section varied so the numbers with each prefix also varied.

Inland later decided to present carbines as gifts to Inland employees, subcontractors, suppliers, members of the military or government, and others to show appreciation for their assistance and cooperation with Inlands war effort. The serial numbers allocated to these carbines were as follows.

Serial Number
Serial Number
X1   X100
XA1   XA100
XB1   XB100*
XC1   XC100
XD1   XD100
XE1   XE100
XF1   XF100
XG1   XG100
* XB271 is a documented exception

This resulted in an unknown number of "presentation" carbines possibly having the same serial number as the earlier Engineering carbines.

The carbines used for this purpose were not from inventory submitted to or accepted by the government. Many were constructed using whatever parts were available. Examples being outdated parts and prototype parts that had accumulated throughout the various departments within Inland over the years of production. This included a few of the previous Engineering carbines no longer needed.

Carbines that have one of these serial numbers may be an Engineering prototype, a "presentation" carbine, or both. They are a specialty that requires each be assessed individually to determine its historical significance. They should not be altered or fired. Doing so may alter their historical value.

Assistance Available

Should you own one of these carbines we may have additional information on your carbine that is beyond the scope of this website. We can be contacted at the following e-mail address.


Carbines with a Serial Number above 8 million

Post WWII, the Office of the Chief of Ordnance (OCO) assigned replacement numbers to armories, arsenals, and depots for carbines having damaged or obliterated serial numbers. Numbers were issued sequentially, beginning where Ordnance had left off with serial number blocks assigned during WWII. The letter X preceding the serial number designated it as a replacement.

The new serial number was hand stamped on top of the receiver behind the rear sight, in the vicinity of the prior serial number.

Quantity StartEnd Assigned to:Date/Notes
-7,369,6618,099,661  Inlandassigned block - M2's
-8,069,6628,084,811  Winchesterassigned block - M3's - not used
Post WWII - Assigned by Office of the Chief of Ordnance - Documents unclear if X added
9 8,084,8128,084,820  "Mr. Thompson", Field Services04 Mar 1949
1 8,084,821   National Guard Bureaudate unk
1 8,084,822   Raritan Arsenal14 Feb 1950
Post WWII - Assigned by Office of the Chief of Ordnance - X Prefix
3 X8,084,823X8,084,825  Raritan Arsenal18 Feb 1950
1 X8,084,826   Missouri National Guard17 Jul 1950
1 X8,084,827   Florida National Guard04 Apr 1951
25 X8,084,828X8,084,852  Rock Island Arsenal15 Jun 1951
1 X8,084,853   California National Guarddate unk
1 X8,084,854   Mt. Ranier Ordnance Depot18 Sep 1951
1 X8,084,855   Raritan Arsenal28 Nov 1951
25 X8,084,856X8,084,880  Mt. Ranier Ordnance Depot10 Dec 1951
200 X8,084,881X8,085,080  Rock Island Arsenal30 Jan 1952
20 X8,085,081X8,085,100  not reported18 Feb 1952
2 X8,085,101X8,085,102  Raritan Arsenal14 Sep 1953
1 X8,085,103   National Guard (no State indicated)15 Jan 1954
1 X8,085,104   Sampson AFB17 Aug 1954

The addition of the serial number on the top of the receiver forward of the rear sight indicates
the serial number behind the rear sight was obscured by an adjustable rear sight.


U.S. Caliber .30 Carbine
Model T3

      4 Digits:     0001-  0835
      5 Digits:   00001-00900
     5 Digits:   01701-07545


U.S. Caliber .30 Carbine
Model T4

   6 Digits:   000001-unknown
(also used standard s/n's)
used standard s/n's


Serial Number stamped Twice

If an adjustable rear sight obscured the serial number, Ordnance personnel were authorized
to also stamp the number on top of the receiver between the rear sight and bolt.

Other Letters

Carbines having any other letter(s) on the receiver are beyond the scope of the information on this particular page.
Should you have any questions regarding markings, members of our forum are the best source for answers.

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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