The U.S. Caliber .30 Carbines - Model T4/M2

The U.S. Carbine Caliber .30

Model T4/M2



M1E7 & T3



Right click on the image to view the model

The Model T4/M2


The original request for submissions in 1940 for what would eventually become the M1 Carbine called for a carbine capable of semi-automatic or select-fire with full automatic capability. During the time leading up to the choice of the Winchester design the select-fire capability was withdrawn in favor of semi-automatic fire only.

In May 1944 research and development was initiated for a group of components that could be added to the standard M1 Carbines to add the capability of select-fire. The project was handled by Winchester in conjunction with Springfield Armory with assistance from Inland. As the select-fire project entered the testing phase the carbines being tested were designated the Model T4 carbines. When the select-fire carbine was adopted in October 1944 the T4 designation was dropped and the carbine was designated The U.S. Carbine, Caliber .30, M2.


Model M2

(T4 photo courtesy Marcus Rust)
    Number of Parts*
    Barrel Length
    Sight Radius
21.5" @ 100 yards
    Overall Length
5.5 lbs
    Trigger Pull
4.5-7 lbs
    Stock Material
Select Fire
    Rate of Fire
750-775 rpm
*number of parts varied as minor changes were implemented and do not include a
complete breakdown of the rear sight and barrel band
Data extracted from
TM 9-1276 Cal. .30 Carbines M1, M1A1, M2, M3, U.S. Government Printing Office, 1953
(paragraph 6, pages 8 & 9)

U.S. Caliber .30 Carbine
Model M2 Production

Inland Div. of General Motors
Feb - Aug 1945
Winchester Repeating Arms
May - Aug 1945
Total: 554,601
Note: Quantities shown were delivered to U.S. Army Ordnance with the markings of the M2.
Many M1's were later converted to select-fire without the M1 markings being changed to M2.

"The carbine M2 is the same as the M1 except for differences in design of certain components and the addition of others ... which permit the M2 to deliver either semiautomatic or full automatic fire." [TM 9-1276 Cal. .30 Carbines M1, M1A1, M2, M3, U.S. Government Printing Office, 1953, paragraph 5, page 3]

The receivers used for the Model M2 were the same receivers that were used for the Model M1. They are interchangeable. The only difference was the M2 marking instead of M1. On some receivers the 1 or 2 was left blank and hand stamped with the appropriate number when the carbine was finally assembled. The M2 marked receivers, with or without any other parts attached, are legally considered machine guns in the U.S.A.

Diagram adapted from U.S. Patent 2,465,487

M2 Components
commonly used during the manufacture of,
and as replacement parts for, the M1:
M2 Components
intended for use
only in the M2:
  • Operating Slide (1)
  • Sear (2)
  • Trigger Housing
  • Stock
  • Selector (A)
  • Selector Spring (B)
  • Disconnector Spring & Plunger (C)
  • Disconnector (D)
  • Disconnect Lever (E)
  • Hammer (F)

The U.S. Department of Justice, Bureau of Alcohol, Tobacco and Firearms (ATF) considers the parts in the right column a conversion kit for full-automatic fire as Ordnance documents indicate these parts were only to be used with carbines capable of automatic fire (TM 9-1276, February 1953). Possession of these parts in a manner they are readily available for use in a carbine is legally considered the same as the parts being within a carbine and thereby a machinegun under U.S. law.

While not designated as a replacement part for the hammer in an M1 Carbine, the M2 Hammer was sometimes used as an expedient field replacement. Sometimes the gap on the right side of the hammer included a field expedient insert to keep the hammer aligned to the left.

To avoid arrest and prosecution for possession of a machinegun the parts in the right hand column should not be together and/or readily accessible anywhere near a carbine.

Post WWII many M1's were modified to select fire carbines by U.S. Army Ordnance. The receivers retained the M1 designation. An M1 or M1A1 Carbine capable of fully automatic fire is legally considered a machine gun in the U.S.A.

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