Several companies manufactured copies of the M1 carbine after World War II, which varied in quality.
Some companies used a combination of original USGI and new commercial parts, while others manufactured entire firearms from new parts, which may or may not be of the same quality as the originals.
These copies were marketed to the general public and police agencies but were not made for or used by the U.S. military.

In 1963, firearms designer Melvin M. Johnson introduced a version of the M1 carbine called the "Spitfire" that fired a 5.7 mm (.22 in) wildcat cartridge known as the 5.7 mm MMJ or .22 Spitfire.
 The Spitfire fired a 40-grain (2.6 g) bullet with a muzzle velocity of 2850 ft/s (870 m/s) for a muzzle energy of 720 foot-pounds force (980 J).
 Johnson advertised the smaller caliber and the modified carbine as a survival rifle for use in jungles or other remote areas.
 While the concept had some military application when used for this role in the selective-fire M2 carbine, it was not pursued, and few Spitfire carbines were made.

More recently, the Auto-Ordnance division of Kahr Arms began production of an M1 carbine replica in 2005 based on the typical M1 carbine as issued in 1944, without the later adjustable sight or barrel band with bayonet lug.
The original Auto-Ordnance had produced various parts for IBM carbine production during World War II, but did not manufacture complete carbines until the introduction of this replica.
 The AOM110 and AOM120 models (no longer produced) featured birch stocks and handguards, Parkerized receivers, flip-style rear sights and barrel bands without bayonet lugs.
 The current AOM130 and AOM140 models are identical except for American walnut stocks and handguards.

In 2014, Inland Manufacturing, LLC in Dayton, Ohio introduced the reproduction of the "Inland M1 Carbine".
 Inland Manufacturing, LLC is a private entity that is producing reproductions of the M1 Carbine and M1A1 Paratrooper models that were built by the original Inland Division of General Motors from 1941 to 1945.
 The new Inland M1 carbines feature many of the same characteristics of the original Inland Carbines and are manufactured in the USA.
 The M1 carbine is modeled after the last production model that Inland manufactured in 1945 and features a type 3 bayonet lug / barrel band, adjustable rear sights, push button safety, round bolt, and "low wood" walnut stock, and a 15-round magazine.
 A 30-round mag catch was utilized to allow high-capacity magazines.
A "1944" M1 Carbine is also available that has the same features as the 1945 only with a Type 2 barrel Band and 10-round magazine and is available for sale in most states with magazine capacity & bayonet lug restrictions.
The M1A1 is modeled after a late production 1944 M1A1 Paratrooper model with a folding "low wood" walnut stock, Type two barrel band, and includes the same adjustable sights which were actually introduced in 1944.

An Israeli arms company (Advanced Combat Systems) offers a modernized bullpup variant called the Hezi SM-1.
The company claims accuracy of 1.5 MOA at 100 yards (91 m).
Several companies manufactured copies of the M1 carbine after World War II, which varied in quality. Some companies used a combination of original USGI and new commercial parts, while others manufactured entire firearms from new parts, which may or may not be of the same quality as the originals. These copies were marketed to the general public and police agencies but were not made for or used by the U.S. military.
In 1963, firearms designer Melvin M. Johnson introduced a version of the M1 carbine called the "Spitfire" that fired a 5.7 mm (.22 in) wildcat cartridge known as the 5.7 mm MMJ or .22 Spitfire.  The Spitfire fired a 40-grain (2.6 g) bullet with a muzzle velocity of 2850 ft/s (870 m/s) for a muzzle energy of 720 foot-pounds force (980 J).  Johnson advertised the smaller caliber and the modified carbine as a survival rifle for use in jungles or other remote areas.  While the concept had some military application when used for this role in the selective-fire M2 carbine, it was not pursued, and few Spitfire carbines were made.
More recently, the Auto-Ordnance division of Kahr Arms began production of an M1 carbine replica in 2005 based on the typical M1 carbine as issued in 1944, without the later adjustable sight or barrel band with bayonet lug. The original Auto-Ordnance had produced various parts for IBM carbine production during World War II, but did not manufacture complete carbines until the introduction of this replica.  The AOM110 and AOM120 models (no longer produced) featured birch stocks and handguards, Parkerized receivers, flip-style rear sights and barrel bands without bayonet lugs.  The current AOM130 and AOM140 models are identical except for American walnut stocks and handguards.
In 2014, Inland Manufacturing, LLC in Dayton, Ohio introduced the reproduction of the "Inland M1 Carbine".  Inland Manufacturing, LLC is a private entity that is producing reproductions of the M1 Carbine and M1A1 Paratrooper models that were built by the original Inland Division of General Motors from 1941 to 1945.  The new Inland M1 carbines feature many of the same characteristics of the original Inland Carbines and are manufactured in the USA.  The M1 carbine is modeled after the last production model that Inland manufactured in 1945 and features a type 3 bayonet lug / barrel band, adjustable rear sights, push button safety, round bolt, and "low wood" walnut stock, and a 15-round magazine.  A 30-round mag catch was utilized to allow high-capacity magazines. A "1944" M1 Carbine is also available that has the same features as the 1945 only with a Type 2 barrel Band and 10-round magazine and is available for sale in most states with magazine capacity & bayonet lug restrictions. The M1A1 is modeled after a late production 1944 M1A1 Paratrooper model with a folding "low wood" walnut stock, Type two barrel band, and includes the same adjustable sights which were actually introduced in 1944.
An Israeli arms company (Advanced Combat Systems) offers a modernized bullpup variant called the Hezi SM-1. The company claims accuracy of 1.5 MOA at 100 yards (91 m).
M1 carbine