November 14, 2023
During World war II, M1 Carbine production was fast, furious and chaotic. The original production contracts for the M1 Carbine were awarded to Inland Manufacturing and Winchester in late 1941. Initial large-scale production began at Inland in late Spring 1942 and in late Summer 1942 at Winchester. Early on, it was obvious that the two primes would not be able to meet production requirements, so additional primes were added to meet demand. The other primes received contracts from early 1942 to early 1943. Production at Inland and Winchester ended in the late summer of 1945, while the other prime contracts were terminated in Spring 1944. It is believed that production ended completely at these smaller primes by early Summer 1944.
The prime contractors for the M1 Carbine were Inland Division of General Motors; International Business Machines (IBM); Irwin Pedersen; National Postal Meter; Quality Hardware; Rock-Ola Music Co.; Saginaw Gear (Grand Rapids S’G’); Saginaw (Saginaw S.G.); Standard Products; Underwood Elliot-Fisher; and Winchester Repeating Arms. Of these, Irwin Pedersen defaulted on its contract in April 1943 and never produced a carbine accepted by the government; all assets and parts were transferred to Saginaw S’G’. However, some sources indicate that approximately 3,540 M1 Carbines were produced by Irwin Pedersen but accepted by the U.S. government through Saginaw.
The number of guns these primes produced for the short time the M1 Carbine was in production is amazing, especially when knowing that only Winchester had ever produced firearms prior. At the beginning of 1942, when the first two production contracts were in place, there was no tooling or fixtures to support mass production. Inland had to produce all the initial tooling and fixtures. In 18 months, 3.1 million M1 Carbines were produced by the start of 1944. Production of the M1 Garand began at Springfield Armory in 1938 and 1941 at Winchester. It took Springfield and Winchester until the summer of 1944 — six years of production — to produce the same number of M1 Garands as the number of M1 Carbines. Production of M1 Garands continued at both places until late Summer 1945, the same time when M1 Carbine production ceased. During the seven-year period, 4,040,802 M1 Garands were produced. In a little more than three years, 6,189,084 M1 Carbines were completed.
By The Numbers
Table 1 shows the approximate total production of each prime. Numbers vary, some depending on the source, hence my use of the word “approximate.” Only a small number of M1 Carbines produced in early 1944 made it to war. Carbine production after this was put into storage, upgraded after the war ended and put back into storage. Many of these late-production guns never saw use until they were sold through the Directorate of Civilian Marksmanship (DCM) during the 1960s and ’70s. Most of these guns were never rebuilt; they simply had upgraded parts added that were not already on the gun. They were new guns, which is why I urge caution when considering the replacement of parts on a gun having many correct-era-type parts. Table 2 illustrates the approximate production of M1 Carbines by year.
As noted, none of the primes produced all the parts for the M1 Carbine on their own, and there were more than 1,500 subs that produced additional parts. Winchester and Underwood made 18 parts; Saginaw S.G. made 17 parts; Rock-Ola made 13 parts; Irwin Pedersen made 11 parts; National Postal Meter and Saginaw S’G’ made seven parts; Standard Products made six parts; Inland made five parts; IBM made three parts; and Quality Hardware only made receivers. Only six of the primes made barrels, those being Inland, Winchester, Underwood, Rock-Ola, Saginaw S.G. and IBM. Standard Products did make a few barrels, but they are extremely rare to the point that they should not be considered for most restorations. Underwood was acknowledged as making some of the best barrels, though.
Both Inland and Underwood are known to have shared receivers with other primes. These are usually identified with the Inland or Underwood receiver markings being lined out and another identifier added to the receiver. For every rule that should apply to M1 Carbine production, there is usually an exception.
Determining the Production Date of an M1 Carbine
Table 3 highlights the contract and serial number blocks assigned to the primes, as well as the approximate date range that these serial number/contract blocks were in place. The dates can only be used as an approximate date range since contracts overlapped and contractors often used serial numbers in sequence rather than by contract. It was not unheard of for contractors to run into another block of a different prime’s serial numbers. Receivers were made and then sat around for several months waiting on other parts (usually barrels). Not all serial numbers were used, either due to production delays or contract terminations. At best, the serial number and Table 3 can be used to approximate the date a receiver was made, but not necessarily when the gun was assembled.
There were two primary types of safeties used on the M1 Carbine, a push-button safety and a rotary lever safety. The push-button safety had three different types of design but only varied externally by a checkered or flat surface. The checkered examples were installed early and into 1943. The push-button safety was used throughout World War II production by all manufacturers. The lever-type safety appeared on later Inland and Winchester guns.
Two types of bolts were used: The original flat bolt and the later round bolt. The round bolt was adopted because it required fewer production processes, which saved time and cost to manufacture. Round bolts began to appear in late 1943. Underwood began using them in late ’43. Inland began using round bolts in late Spring to Summer 1944. By October ’44, only round bolts were used. Winchester began installing round bolts in the Summer of ’44 and, by January 1945, exclusively used round bolts. The other primes began using round bolts in early 1944 and production remained mixed until the end of production in the Spring to Summer of ’44. Flat bolts were usually blued, but not always! Round bolts were both blued and Parkerized.
There were two basic types of trigger housings: A milled housing and triggerguard, as well as a milled trigger housing with a stamped metal triggerguard, which was brazed to the milled trigger housing. The later stamped type was developed to reduce cost, but it was not universally adopted. Some manufacturers felt the added operations of stamping and then brazing did not save enough time or cost to bother with.
IBM used a stamped triggerguard throughout production. Underwood started using a stamped triggerguard mixed with a milled unit in the Spring of 1943 until the end of production (EOP). Underwood stopped using the milled trigger housing completely by late 1943. Standard Products used a milled trigger housing to the end of ’43. They began using the stamped triggerguard in September 1943 until the EOP. Quality Hardware used a milled trigger housing to the end of 1943. They started using the stamped triggerguard in September 1943 until the end. Rock-Ola featured a milled triggerguard into late 1943. They, too, began using a stamped triggerguard in the summer of 1943 until the EOP. Saginaw-Grand Rapids installed a milled trigger housing to its end, but it began incorporating some stamped triggerguards during the Fall of 1943 until the EOP. Inland, Irwin Pedersen, National Postal Meter, Saginaw S.G. and Winchester only used milled trigger housings.
There were six types of magazine releases used during production. The face of the release was either flat or serrated. The later magazine release, designed for the heavier 30-round magazine, had an “M” or an “M” stamped on the flat-push surface. Inland began using the magazine release with an “M” on it in Spring 1943 to EOP. Saginaw (S.G.) used the “M”-marked release in late-production guns. Winchester began using the “M”-marked release in late ’43 until EOP. Winchester and Inland used some “M”-marked releases in late-production ’45 guns. The other primes began using some “M”-marked releases from late ’43 to early ’44.
As mentioned, only six of the primes produced barrels. If you have an M1 Carbine built by a producer that did not make barrels, do some research to investigate and identify the likely barrel suppliers for your M1 Carbine.
There were two types of operating slides used on war-production M1 Carbines. There were several subsets within the two types that had small differences. The Type A slide had a straight bolt-lug boss that curves over the front of the receiver and engages the bolt lug. The Type B slide has an undercut or curved bolt-lug boss.
Inland and Winchester were the only primes that used large quantities of the Type B slide. Type B slides were used on the late production of the smaller primes, especially those that produced into late Spring or early Summer 1944. Winchester began using the Type B slide in early ’44 and used only the Type B by Summer 1944. Inland began using the Type B slide in Spring 1944 and used only the Type B by Summer 1944.
There were three barrel-band types used on M1 Carbines. The Type A band is a narrow version with a screw on the left side capturing the sling swivel. The Type B is a wider band with a screw on the bottom and a sling swivel on the left side, welded in the middle and retained by a stamped metal loop. The Type C band was identical to the Type B, only with a bayonet lug extension added to it. The Type C band was only used by Inland and Winchester, making its first appearance in mid-1944. By the EOP, only one-in-three M1 Carbines were produced with a Type C band. Details to inspect on an M1 Carbine are the proofmarks and production date stamped on the barrel. Be sure they were never covered by the bayonet lug. If the bayonet lug covers the proofmarks, it did not have a Type C band originally.
Type B bands were used in early 1944 and through the late production of the eight smaller primes. They were mixed with Type C bands by Inland and Winchester until EOP.
There were three types of front sights, two versions were milled and the third was a stamped and brazed sight. Within the milled sights, Winchester only used a sight that had a slight convex arc on the rear slope. Every other manufacturer used a sight with a straight slope at the rear of the sight. From mid-1943 on, all manufacturers — other than Inland, Saginaw (S’G’), Irwin Pedersen and Winchester — used the stamped and brazed sight.
On to Part 3...
Parts 1 and 2 were not all-inclusive dissertations on identifying and restoring M1 Carbines to wartime production configurations. This article was written on the backs of researchers including Bruce Canfield, Scott Duff, Jesse Harrison, and Larry Ruth. Ron Norton of Inland Manufacturing was also critical to this article. It was written to inspire and whet the appetite of those desiring to restore an M1 Carbine. Part 3 will conclude this series with the restoration and evaluation of a Rock-Ola M1 Carbine.
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