Inland M1 Carbine Serial Number Date Of Manufacture

Inland Division Of General Motors M1 Carbine 'X' Series Serial Number Description: This Inland has the barrel date of 8-45. Reassembly required the use of new rivets. During WWII the M1A1 stocks and parts in the possession of Springfield Armory, whether made by Springfield or another manufacturer, were for use as replacements. 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.

M1 Carbine Serial Number Lookup

Inland General Motors M1 Carbine' />Gun Test Inland Mfg. New Production MBy Kelly Young, American Rifleman. Long decades have passed since the M1 carbine was removed from military service, but the years have done little to diminish the popularity of the diminutive rifle. Today, thanks to a variety of factors, the Light Rifle still enjoys one of the broadest fan bases in the gun worldand in many ways a high quality, modern reproduction is just as appealing as a wartime relic. For one, it is easy for virtually anyone to use. Short, light, well balanced, soft recoiling and fast firing, it is a joy to shoot for even the small statured and recoil averse. AR_M1inland-e1461182351265.jpg' alt='Inland Division M1 Carbine Value' />Secondly, due to its unique production history, with numerous manufacturers making countless iterations of the same model, the M1 carbine is a gun collectors dream. But ask a collector if you can take a few shots through one of his mint prized pieces, and his eyes will likely go wide with trepidation. On the other hand, a replica that looks, handles and shoots as well, if not better, than the original provides the same experience without the risk of anything unpleasant happening to diminish the value of a cherished heirloom. Nostalgia also plays a role in the continued popularity of the platform, as veterans, and their family members, are often keen to own a high functioning facsimile of the arm they or a loved one once carried into war. The Inland Manufacturing Division of General Motors produced more than 2. M1 carbines between 1. World War IIapproximately 4. With total production exceeding 6. Sybase Jconnect 7. M1 carbine was the most prolifically manufactured American small arm of World War II, and no firm produced more than the Inland Manufacturing Division of General Motors. But while the original Inland left the firearm industry nearly 7. American made M1 carbines bearing the Inland name. Precisely reproduced from the original specifications, and built using 1. Inland offers a full line of carbines that look and feel just as good as the genuine articleand, in most cases, shoot even better. The U. S. Carbine,. Caliber, M1, much more commonly known as the M1 carbine, was created in response to a U. S. Army requirement for a Light Rifle to augment the standard issue M1 Garands already in service. How to check serial numbers for m1 carbines How Tos. Inland Division of General Motors 1. Inland manufacturing. General Motors M1 CarbinePrimarily intended for use by rear echelon troops who, until that time, had either been unarmed or carried only a sidearm, the carbine was also issued to specialized frontline troopssuch as signal corps personnel and crew served weapon operatorswho were likely too encumbered with their own equipment to also wield the sizeable Garand service rifle. Many gunmakers provided entrants for the government trials however, it was the Winchester designthat company having already developed the Light Rifle projects rimless,. Carbinethat received the unanimous support of the Ordnance committee. Initially only two companies were contracted to produce the new rifles, Winchester and Inland. It quickly became apparent that demand would far outpace supply, and eight other facilities including incongruous choices such as IBM, National Postal Meter and Rock Ola would eventually tool up to build M1 carbines, as well. How To Make 2 Health Bars In Game Maker there. Carbine Rifle ManufacturersThe Inland Manufacturing Division of General Motors had been created in October 1. World War II had expanded its operations to fabricate more than 1,3. Operating out of Dayton, Ohio, in the very hangers that once housed Orville and Wilbur Wrights defunct Wright Airplane Co. Inland was already churning out war matrielsuch as plastic helmet liners, anti aircraft gun sights and tank tracksprior to its involvement with the M1 carbine. M1-1944/M1-1944-A.jpg' alt='Inland Arms M1 For Sale' />Inland Manufacturing Division was formed on January 6. Not all serial numbers were. This Inland built M1 Carbine is on display at Fort Macon State Park in. M1 Carbine date of manufacturing. Is there any way of finding out the date of manufacture for an M1 Carbine It is an Inland Division M1. These serial numbers are. This album contains images of my Inland M1 Carbine built. Ohio by the Inland Manufacturing Division of the General Motors Corporation. Based on the serial. How do I verify the age of my M1 Carbine It says U. S. CARBINE CAL. 30 M1 above the barrel. On the front of the barrel I can see INLAND MFG. Inlands product line of era accurate M1 carbines includes long guns and the Advisor above a handgun. The first production run of M1 carbines left the Inland plant in early 1. V J Day Aug. 1. Originally, Inland was to ship 2. Later in 1. 94. 2, a wire stocked variant of the carbine, the M1. A1, was created and adopted by the military, and Inland was the exclusive manufacturer of the paratrooper friendly carbines. Inlands engineering department was also responsible for the development of the M2 carbine and the FP 4. Liberator pistol which was subsequently produced by GMs Guide Lamp Division. All told, during a three year period, Inland produced a total of 2,6. M1 carbinessingle handedly responsible for roughly 4. The M1 carbine would go on to see combat in both Korea and Vietnam, remaining in service long after many of its contemporaries had been forced into retirement. At the conclusion of World War II, Inland returned to automotive manufacturing, and in 1. GM properties and was eventually spun off from the parent company in 1. This would have been the end of the Inland story, were it not for veteran, former U. S. Army Marksmanship Unit member and firearm developer Ron Norton, who founded Inland Mfg., LLC, a few years ago and set up shop just two short miles from where the original GM plant stood. The city of Dayton has always taken great pride in its historic ties to the old Inland plant, and as a Dayton native himself, Norton had grown up with a special appreciation for the M1 carbines produced there. So when he left Chiappa Firearms, Ltd., in 2. Inlands M1s not only came naturally to Norton it was a project close to his heart. At the time of this writing, Inlands product line stood at four M1 carbine based modelsthree rifles M1 1. M1 1. 94. 5 and M1. A1 and the Advisor handgunhowever several new models were introduced at SHOT Show 2. Inland Manufacturing Division M1 Carbine Serial Numbers' />For more information regarding these recent additions, visit americanrifleman. Throughout its production life, the M1 carbine continually evolved, as upgrades and design modifications through the years led to alterations to numerous component partsincluding the wood stock, trigger housing, extractor, recoil plate, magazines and safety, among othersas well as changes in barrel steel and annealing methods. This constant progression is reflected in Inlands catalog of M1s, which all share the same guts, yet vary in terms of furniture, features and accessories. Like their storied forebear, Inlands new M1 carbine models rely on a short stroke gas piston system in order to cycle. Gas siphoned from the barrel pushes a tappet style piston back roughly 13 to strike the operating slide, which, during its rearward movement, cams a rotating bolt to unlock the action and extract the spent case. Following ejection of the case, the recoil spring assembly then returns the operating slide forward again, causing the bolt to strip a fresh cartridge from the detachable box magazine and chamber it prior to locking into the receiver. The bolt can be locked back using a pin located on top of the slide. To activate, just pull the slide back fully and then depress the pin until it nests within an indentation in the upper surface of the receiver. Remove Programs From Vista Start Menu. The internal workings of new production Inland M1 carbines will be familiar to those already accustomed with the original World War II vintage rifles, as they are built to the same specifications. The new carbines are produced using both steel components and stocks that meet the original G. I. specifications, meaning that parts for the new guns will interchange with those assembled during the war. Built on investment cast receivers, most of the metal parts on the new guns bear a Parkerized finish, and the included staggered column magazine has been blued.

The U.S. Carbine Caliber .30

U.S. Army Ordnance
Serial Number Assignments

Serial Number Tables

Models M1, M1A1, M2
By Prime Contractor	Table A
Numerical Order	Table B
Subcontracted Receivers	Table C
Leftover Receivers used by Winchester	Table D
Transferred Receivers	Table E
Duplicated Serial Numbers	Table F
Irwin-Pedersen, Grand Rapids, & Saginaw	Table G
Inland Mfg - Engineering & Presentation Gifts	Table H
8 Million Serial Numbers	Table 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

TABLE A
Prime Contractor

Prime Contractor	Start	End
IBM	3,651,520	4,009,999
Inland	1	5
	11	999,999
	2,912,520	3,212,519
	4,879,526	5,549,821
	6,219,689	6,449,868
	6,629,884	7,234,883
	7,369,661	8,069,661
National Postal Meter	1,450,000	1,549,999
	1,937,520	1,982,519
	4,075,010	4,432,099
...as Commercial Controls ⁽¹⁾	001	239
Quality Hardware	1,550,000	1,662,519
	1,875,040	1,937,519
	4,432,100	4,532,099
	4,632,100	4,879,525
Rock-Ola	1,662,520	1,762,519
	4,532,100	4,632,099
	6,071,189	6,099,688
	6,199,689	6,219,688
Saginaw (S.G.)	3,250,020	3,651,519
Saginaw (S.G.)	5,834,619	6,071,188
Saginaw (S'G')/Irwin-Pedersen	1,762,520	1,875,039
Saginaw (S'G')/Irwin-Pedersen	3,212,520	3,250,019
Standard Products	1,982,520	2,352,519
Underwood	1,350,000	1,449,999
	2,352,520	2,912,519
	4,010,000	4,074,999
	6,099,689	6,199,688
Winchester	6	10
	1,000,000	1,349,999
	4,075,000	4,075,009
	5,549,922	5,834,618
	6,449,884	6,629,883
	7,234,884	7,369,660

TABLE B
Numerical Order

Start	End	Prime Contractor	Notes
1	5	Inland	Toolroom Models ⁽²⁾
6	10	Winchester	Toolroom Models ⁽²⁾
11	99	Inland	Engineering ⁽³⁾ & Experimental ⁽⁴⁾
100	999,999	Inland	(see Tables C, E, F)
1,000,000	1,349,999	Winchester
1,350,000	1,449,999	Underwood
1,450,000	1,549,999	National Postal Meter
1,550,000	1,662,519	Quality Hardware
1,662,520	1,762,519	Rock-Ola
1,762,520	1,875,039	Irwin-Pedersen/Saginaw (S'G')	(see Table G)
1,875,040	1,937,519	Quality Hardware
1,937,520	1,982,519	National Postal Meter
1,982,520	2,352,519	Standard Products
2,352,520	2,912,519	Underwood	(see Tables C, D, E)
2,912,520	3,212,519	Inland	(see Table C)
3,212,520	3,250,019	Irwin-Pedersen/Saginaw (S'G')	(see Table G)
3,250,020	3,651,519	Saginaw (S.G.)	(see Table G)
3,651,520	4,009,999	IBM	(see Tables C, E, F)
4,010,000	4,074,999	Underwood
4,075,000	4,075,009	Winchester	Winchester gift guns
4,075,010	4,432,099	National Postal Meter	(see Table C)
4,432,100	4,532,099	Quality Hardware (UN-QUALITY)	(see Table C)
4,532,100	4,632,099	Rock-Ola
4,632,100	4,879,525	Quality Hardware
4,879,526	5,549,821	Inland
5,549,822	5,549,921	not assigned
5,549,922	5,834,618	Winchester	(see Tables D, F)
5,834,619	6,071,188	Saginaw (S.G.)
6,071,189	6,099,688	Rock-Ola
6,099,689	6,199,688	Underwood
6,199,689	6,219,688	Rock-Ola
6,219,689	6,449,883	Inland
6,449,884	6,629,883	Winchester
6,629,884	7,234,883	Inland	Model M1 & Model M2
7,234,884	7,369,660	Winchester	Model M1 & Model M2
7,369,661	8,069,661	Inland	Model 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

Notice

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.

TABLE C
Subcontracted Receivers

(also see Table E)

Lowest	Highest	Prime Contractor	Code	Subcontractor	Notes
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-QUALITY	Union Switch & Signal

TABLE D
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.

Winchester removed the Underwood name and serial number, then replaced them with the Winchester name and serial number.

Winchester sometimes lined out the Underwood name, sometimes not.

- The significance of the letter A is unclear.

Lowest	Highest	Info	Code
1,244,697	1,290,339	Underwood name removed, Winchester name & s/n	A W
2,38x,xxx	2,404,928	Underwood name not lined out, Underwood s/n	WTA
2,485,125	2,491,867	Underwood name not lined out, Underwood s/n	WwA
5,759,1xx	5,801,924	Winchester name, Winchester s/n	T
5,814,798	5,820,062	Underwood name removed, Winchester name & s/n	A W
6,461,479	6,482,225	Underwood name lined out, Winchester s/n	A W, W A
6,473,811	?	Underwood name lined out, Winchester s/n	No Code
6,497,153	6,614,551	Underwood name lined out, Winchester s/n	B, BA, ABW, BW

TABLE E
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.

Lowest	Highest	Info	Code
126,794	127,006	Inland s/n'd receivers sent to National Postal Meter	N
438,xxx	590,828	Inland s/n'd receivers sent to Rockola	Rockola
496,xxx	634,161	Inland s/n'd receivers sent to Underwood	·U·
702,607	?	Inland s/n'd receivers from SI subcontract sent to Underwood	·U·
724,318	751,395	Inland s/n'd receivers from SG subcontract sent to Underwood	·U·
1,765,761	1,769,771	Irwin Pedersen s/n'd receivers sent to Underwood	·U·
2,743,286	2,770,326	Underwood s/n'd receivers sent to National Postal Meter	N
3,842,177	3,846,371	IBM s/n'd receivers from AO subcontract sent to National Postal Meter	N
4,049,244	?	Underwood s/n'd receivers sent to National Postal Meter	N

TABLE F
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

TABLE G
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 Range		S/N Block Reassigned to	Markings on Receivers	Notes
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 Range		S/N Block Assigned to	Markings on Receivers	Notes
3,250,020	3,651,519	Saginaw	SG	SG 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 Range		S/N Block Assigned to	Markings on Receivers	Notes
3,249,020	3,250,019	Grand Rapids	S'G', some SG	possibly 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 Range		S/N Block Assigned to
3,541,000	3,651,519	Saginaw

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.

TABLE H
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.

Start Serial Number	End 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.

TABLE I
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.