Johnson Arms

Post WWII Commercially Manufactured M1 Carbines (U.S.A.)

    Johnson Arms, Inc.
    New Haven, CT



Melvin Maynard Johnson Jr. was a firearms inventor and designer who is probably best known for the rifle he developed and submitted to the U.S. military in 1939 as an alternative to the .30 cal. Rifle, Model M1 (M1 Garand). It failed to replace the M1 Garand but was purchased in limited quantities and designated the M1941. It was used by U.S. forces for a brief time during WWII and purchased by several other countries after WWII.

Johnson M1941 Rifle

Johnson is also well known for his M1941 Light Machine Gun. Purchased by the U.S. military in slightly larger quantities than his M1941 Rifle and used by special units of the U.S. military during WWII.

Johnson manufactured both weapons at Universal Windings Corporation in Cranston, RI. While Universal Windings also manufactured M1 carbine receivers under a subcontract from Underwood, Elliott, and Fisher in Harford, CT during 1943.

Johnson's designs and inventions before and during WWII were primarily intended for use by the U.S. military. After WWII his company, Johnson Automatics Corporation in Providence, RI, experienced financial difficulties that led to it being purchased by Winchester in 1949. Johnson worked at Winchester for a short time then as a weapons consultant for the government and various companies that included Armalite and Colt.

Johnson was aware of the U.S. military's ongoing interest in a small-caliber, high-velocity firearm. An interest that in the 1950's led to the development of the .223 caliber M16 rifle to replace the M1 Garand. He was also familiar with the U.S. .30 caliber carbine and its use as a front-line combat weapon during WWII and Korea. Even though the carbine had been developed and adopted as a compact light rifle alternative to the 1911 pistol for use by support personnel. Front-line troops who had used it had complained the .30 cal. carbine cartridge was under-powered and inadequate.

By 1961 Johnson was experimenting with the idea of converting caliber .30 carbines for use with a more lethal small-caliber high-velocity round. He foresaw the potential for military contracts if he could come up with a cost effective conversion for the millions of existing carbines produced during WWII that were soon to become government surplus. Johnson wasn't the first to experiment with various small-caliber high-velocity rounds for use with the carbines.

Johnson Guns Inc. was incorporated in Connecticut during December 1961 for the production, procurement, and sales of his conversion.

Johnson submitted a proposal for the conversion to the Defense Department's Advanced Research Projects Agency early on. In February 1962 Johnson learned the agency was not interested. This eliminated the possibility of the U.S. military adopting his conversion for use with the military's existing M1 carbines. Johnson's focus then changed to use by special forces, law enforcement, civilians, and foreign sales.

The Cartridge

The cartridge developed by Johnson used a .30 caliber carbine casing necked down to hold a 40 grain .2235 caliber bullet. Using 11.5 grains of #4227 powder produced a muzzle velocity of 2,850 fps out of an 18" barrel. In addition to speed the advantages of this ammunition included a flatter trajectory, penetration, and significant damage caused by a bullet that tumbled on impact.

Johnson named the cartridge the MMJ 5.7mm (commonly referred to as the Johnson MMJ 5.7mm). Cartridges were available with full metal jacketed bullets and soft point bullets.

.30 caliber CarbineMMJ 5.7mm
Casing.30 caliber Carbine.30 caliber Carbine
Primersmall rifle#6.5
Bullet diameter.308".2235"
Bullet weight110 grains40 grains
Muzzle velocity*1990 fps2850 fps
Muzzle energy*967 ft lbs720 ft lbs
* 18" barrel

Johnson's efforts to have his MMJ 5.7mm cartridge commercially produced in quantity were never successful. Standards for the manufacture of American firearms ammunition are established by the Sporting Arms and Ammunition Manufacturers' Institute, Inc. (SAAMI). This cartridge is not included in SAAMI's standards. It has not been standardized.

Since the 1960's several companies have manufactured and sold slight variations of this cartridge as the 5.7mm Johnson Spitfire, 5.7mm Johnson, or 5.7mm MMJ. Collectively these cartridges have also been referred to as the .22 Spitfire, .22 MMJ Spitfire, .22 Carbine, and 22-30 Carbine.

Anyone owning or considering the purchase of a firearm and/or ammunition identified as one of these needs to be aware there have been slight variations in bullet diameters and barrel bores that can become a safety hazard if the wrong ammunition is used in a firearm having different bore dimensions. The data indicated in various ammunition reloading publications is not based on a well established standard and will not apply to every carbine with a caliber indicated by one of these names.

The most reliable source for this ammunition and the variations can be found on the Johnson Rifle Site Bulletin Board.

The Carbines

Modification of the receiver feed ramp and barrel were the only alterations required to convert the .30 caliber carbines for use with the MMJ 5.7mm cartridge.

Existing barrels were relined for the 5.7mm cartridge and their gas system was modified. New barrels incorporated these changes in their manufacture. A feed ramp insert was installed when converting existing carbines. With new receivers, the feed ramp was machined for the MMJ 5.7mm during the manufacturing process.

Johnson Guns, Inc.
Hamden, CT

The two models initially offered were termed a "Sub-Rifle". Both had a shortened wood stock with a folding wire shoulder stock. The model for purchase by the military and law enforcement featured a 12" barrel and was marketed as a guerrilla or jungle carbine. The model for civilians had an 18" barrel and was marketed as as a varmint and survival rifle. Either could be purchased as a new carbine or for modification of the owner's existing carbine. By the time they were ready for production the "Sub-Rifles" were renamed "Spitfires".

Melvin Johnson
with his 5.7mm Spitfire for
use by the Military and Police
Action:    Semi-Automatic only
Sights:    GI type
Barrel:    12" (6 groove)
Overall length:    19" overall with stock folded
Weight:    slightly over 4 1/2 lbs.

Johnson Model JSSR 5.7mm Spitfire
for use by Civilians
Action:    Semi-Automatic
Sights:    GI type
Barrel:    18" (6 groove)
Overall length:    27" overall with stock folded
Weight:    slightly over 5 lbs.
also available with full size carbine stock

The test gun provided to the editors of Shooting Times Magazine (June 1963 issue) was manufactured by Universal Firearms in Hialeah, FL. By August 1963 Plainfield Machine Company in Middlesex, NJ, indicated they would be manufacturing the Spitfires.

The Courier News, Plainfield, NJ, 29 Aug 1963

An article entitled "PMC is Exclusive Maker of the Johnson "Spitfire" Developed by
Melvin M. Johnson Jr.", was published in The Central NJ Home News on 19 Jan 1964.

Thereafter all new carbines in MMJ 5.7mm offered and sold by the Johnson companies were manufactured by Plainfield Machine Company.

Johnson Guns, Inc.
Hamden, CT

The civilian version of the shortened carbine was discontinued in 1964. Civilians were now offered two sporter versions.

Johnson 5.7mm Spitfire
Model JSM
Standard Sporter
Action:    Semi-Automatic
Front Sight:    Williams Gun Sight Ramp and Bead
Rear Sight:    Williams Model WGRS adjustable peep sight
Stock:    Sporterized
Barrel Length:    18"
Overall length:    36"
Weight:    5 1/2 lbs.

Johnson 5.7mm Spitfire
Model JSCD
Deluxe Sporter

American Rifleman Magazine
October 1964
Action:    Semi-Automatic
Front Sight:    Williams Gun Sight Ramp and Bead
Rear Sight:    Williams Model WGRS adjustable peep sight
Stock:    Sporterized with Deluxe Hand Checkering
Barrel Length:    18"
Overall length:    36"
Weight:    5 1/2 lbs.
Drilled and tapped for Williams Gun Sight side scope mount,
includes Bucheimer model 840 red gun case

Use of the GI type front sight was discontinued as the flatter trajectory of the MMJ 5.7mm cartridge required
a higher front sight. The front sight was now a Williams Guns Sight bead sight mounted on an extended ramp.

Williams Gun Sight Model WGRS adjustable peep sight
(rear sight shown in advertisements is not the WGRS)

Melvin Johnson holding what appears to be his Standard Sporter 5.7mm Spitfire Carbine.
Also shown are his M1941 Rifle (left), M1941 Light Machine Gun (front),
and a Sako bolt action rifle in MMJ 5.7mm (right).

Various articles and reviews appeared in many different publications throughout 1963. But problems with their suppliers/contractors held up production. By December 1964 these problems resulted in Johnson Guns, Inc. filing for Chapter 11 bankruptcy.

After a reorganization, the company emerged from bankruptcy as Johnson Arms, Inc. in New Haven, CT.

Johnson Arms, Inc.
New Haven, CT

During a business trip to New York City with his son Edward in January 1965, Melvin Johnson suffered a heart attack and died at the age of 55. Johnson Arms was taken over by Edward, who had been his father's right-hand man with Johnson Guns.

Johnson Arms offered four models of new 5.7mm Spitfire carbines along with a fifth model for conversions of existing carbines. The shortened carbine for military and law enforcement was discontinued. It was replaced by a full size carbine equipped with a telescoping stock.

Model 5770

  Caliber:  MMJ 5.7mm  Front Sight:  Williams ramp sight
  Action:   semi-automatic  Rear Sight:  Williams WGRS peep sight
  Barrel:   18"
  6 grooves with 1 turn in 16"
  Stock:   Select American Walnut,
  low profile walnut handguard,
  Monte Carlo comb, hand checkered
  grip and forearm.
  Bolt:   Damascened (engine turned)   Overall Length:  37 1/2"
  Receiver:   tapped for Williams side scope mount  Weight:  5 lbs (empty)
  Finish:   Luster-rich blue  Magazine Capacity:  5, 15, 30 rounds

The only differences between the Model 5770 and Model 5771 were the handguard, bolt, and magazines.
This model never entered production. Only one was made. For use as a demo.

Model 5771

  Caliber:  MMJ 5.7mm  Front Sight:  Williams ramp sight
  Action:   semi-automatic  Rear Sight:  Williams WGRS peep sight
  Barrel:   18"
  6 grooves with 1 turn in 16"
  Stock:   Select American Walnut,
  Monte Carlo comb, hand checkered
  grip and forearm
  Bolt:   polished   Overall Length:  37 1/2"
  Receiver:   tapped for Williams side scope mount  Weight:  5 lbs (empty)
  Finish:   Luster-rich blue  Magazine Capacity:  5 rounds

Receiver ring markings identify Johnson Arms as the manufacturer along with the rifle caliber. An example
is shown below with the Model 5772. All models that were new carbines were given a four digit serial
number on top of the receiver in front of the rear sight.

Model 5772

  Caliber:  MMJ 5.7mm  Front Sight:  Williams ramp sight
  Action:   semi-automatic  Rear Sight:  Williams WGRS peep sight
  Barrel:   18"
  6 grooves with 1 turn in 16"
  Stock:   Select American Walnut
  Bolt:   polished   Overall Length:  37 1/2"
  Receiver:   tapped for Williams side scope mount  Weight:  5 lbs (empty)
  Finish:   Luster-rich blue  Magazine Capacity:  5 rounds

Example of the receiver ring markings used on all new carbines

Model 5773

  Caliber:  MMJ 5.7mm  Front Sight:  Williams ramp sight
  Action:   semi-automatic  Rear Sight:  Williams WGRS peep sight
  Barrel:   18"
  6 grooves with 1 turn in 16"
  Stock:   American Walnut,
  Bianchi retractable shoulder stock
  Bolt:   polished   Overall Length:  37 1/2" extended, 27 1/2" retracted
  Receiver:   tapped for Williams side scope mount  Weight:  5 lbs (empty)
  Finish:   Luster-rich blue  Magazine Capacity:  5 rounds

The Bianchi telescoping stock for the M1 carbine was designed by John Bianchi and Bob Penney based on the stock of the M3 Grease Gun. It was
manufactured in the mid to late sixties by Wayne's Wood Carving in Los Angeles. Several manufacturers purchased the Bianchi stock
and included it as standard on some of their carbines. It was also available as an accessory from Bianchi and many different retailers.

Shotgun News January 1, 1966

Model 5774

  Caliber:  MMJ 5.7mm  Front Sight:  Williams ramp sight
  Action:   semi-automatic  Rear Sight:  (as provided by customer)
  Barrel:   18"
  6 grooves with 1 turn in 16"
  Stock:   (as provided by customer)
  Bolt:   (as provided by customer)  Overall Length:  37 1/2"
  Receiver:   (as provided by customer)  Weight:  5 lbs (empty)
  Finish:   Luster-rich blue  Magazine Capacity:  (as provided by customer)
additional features available at extra cost

The Model 5774 was the designation given to all of the existing .30 cal. carbines converted to 5.7mm Johnson.

These carbines retained their original markings and serial number.

MMJ 5.7mm was added to the top of their receiver
between the bolt and rear sight platform.

Shotgun News, January 1966

Closure of Johnson Arms

Johnson Arms was closed in 1967 due to the lack of military contracts, ongoing problems with having the ammunition mass produced, and an insufficient number of customers to keep the company going. The volume of .30 carbine ammo readily available while the MMJ 5.7mm was not likely contributed to a lack of customers. Their remaining inventory was sold to Sarco in Stirling, NJ.

"5.7mm Johnson" Carbines
by other Manufacturers

Interest in the MMJ 5.7mm cartridge has not been widespread but it has remained popular with a number of carbine owners. Over time a number of .30 caliber carbine manufacturers have also offered models in "5.7mm Johnson", 5.7mm Spitfire, .22 Spitfire, .22 carbine, or various other names by which the cartridge has come to be known. Most discontinued them due to limited interest. Probably in no small part due to the lack of an ammunition manufacturer willing to mass produce the cartridge. Off and on several ammunition manufacturers have offered the cartridge in limited quantities but most who own one of these carbines have had to reload their own ammunition.

Anyone interested in this cartridge and the carbines that use them should be aware there have been minor variations to the ammunition and carbines that have deviated from what was used by Johnson Guns/Johnson Arms. One example is some have used a .224 caliber bullet that requires a slightly larger bore diameter and should not be used in carbines intended for use with the .223 caliber bullet. Refer to the section below for additional resources that may assist with this challenge.

Plainfield Machine Company

Plainfield Machine began offering their own 5.7mm Johnson caliber carbines about 1964 and continued off and on thru their end of production in 1978. Their catalogs, brochures, and advertisements listed these as .223 PMC caliber. Possibly to avoid conflict with Johnson's trademarked "MMJ 5.7mm".

Plainfield Machine
22 PMC (5.7mm Johnson Caliber) Carbines
Model #Model DescriptionStockHandguardFinishMisc.
PM 22322 PMCAmerican Walnut w/ slingwell  ventilated metal  bluedstandard carbine
PM 223 DDeluxe 22 PMCPremium Grade American Walnut, high comb  ventilated metal  bluedcustom barrel band
PM 223 T22 PMCAmerican Walnut w/ slingwell  ventilated metal  blued22" barrel, 4x scope w/ S&K mount

Plainfield Machine 1970 brochure

Markings used on these models throughout production

Serial numbers for their PM 223 models started with the letter A. Several years prior to their PM 223 models the serial numbers of their very first .30 cal. carbines had started with the letter A.

Iver Johnson Arms

Plainfield Machine was purchased by Iver Johnson Arms (not to be confused with Johnson Arms) in 1977. Iver Johnson took over the Plainfield Machine facility in New Jersey where they manufactured carbines until 1982.

Iver Johnson Arms was purchased in 1983 by an Arkansas group and relocated to Jacksonville, AR. They went thru another change in ownership early in 1986 but remained in the Jacksonville, AR facility until closed by a bankruptcy in 1992/1993.

Iver Johnson Arms used "5.7mm Johnson" to identify the caliber of these models. They were offered occasionally throughout their company's lifespan 1978-1992.

ModelDescriptionStockFinish*CaliberBarrelYearsSerial Number
PM5.7 MilitaryHardwoodBlued5.7mm Johnson18" 1983 EA
PM5.7HBMilitaryHardwoodBlued5.7mm Johnson18" 1984-1985 EA
PM5.7S MilitaryWalnutStainless Steel5.7mm Johnson18" 1983 ES
PM5.7WSMilitaryWalnutStainless Steel5.7mm Johnson18" 1984-1985 ES
SC5.7F SurvivalFolding ZytelBlued5.7mm Johnson18" 1983 EA
SC5.7FS SurvivalFolding ZytelStainless Steel5.7mm Johnson18"1983 ES
SC5.7S SurvivalStandard ZytelBlued5.7mm Johnson18" 1983 EA
SC5.7SS SurvivalStandard ZytelStainless Steel5.7mm Johnson18"1983 ES

Iver Johnson Carbines in 5.7mm Johnson
Iver Johnson Catalog 1983

Iver Johnson receiver markings varied over time but
consistently indicated the caliber as 5.7mm. M-5
was a holder-over from Plainfield Machine and
used by Iver Johnson in New Jersey 1978-1982

iai American Legends

Israel Arms International began manufacturing .30 cal. carbines in 1996. They changed their name to iai American Legends in 2002. After the name change, they also began offering carbines and "conversion kits" in ".22 Spitfire". At least one and possibly two ammo manufacturers began offering 5.7mm Johnson Spitfire ammunition for iai's carbines. But iai ceased doing business in 2003, soon after the ammunition first became available.

All carbines manufactured by IAI/iai, the .22 Spitfire included, were designated the Model M888.

The caliber on iai's .22 Spitfire receivers was indicated as Cal 22 ML.
ML was also used on their .30 cal. carbines instead of M1.

The "conversion kit" consisted of a barreled receiver with front sight, rear sight, barrel band,
and gas piston. Included were a 15 round magazine along with ammunition samples and reloading
data for the 5.7mm Johnson Spitfire ammunition.

Leftover receivers, barrels, and parts were acquired by several different companies when iai closed. Some purchased or obtained in lieu of money owed. This included .22 Spitfire barrels. Some of which were later sold by Numrich Gun parts. iai's barrels had no caliber or manufacturer markings.

Liberty Armory

Liberty Armory was a restoration business owned and operated by Larry Horner in Liberty, TX. Horner had been hired by the owners of IAI/iai to assemble their carbines. Horner's final payment from iai when they went out of business in 2003 was leftover carbine receivers and parts that included the items iai had sold in their .22 Spitfire conversion kits.

Horner assembled and gifted or sold a number of carbines in 2003/2004. It's not known if any were .22 Spitfires. Most retained their iai markings and serial numbers. To which he added the Liberty Armory name on the left side of the receiver under the serial number below the stock line. Horner built a few as presentations/gifts. These also retained the markings used by iai on the receiver ring. The iai Houston, TX markings on top of the receiver behind the rear sight were replaced with the Liberty Armory name and a new serial number.

If Horner assembled any of the carbines as .22 Spitfires, they would have retained their iai markings shown with iai above.

Fulton Armory

Fulton Armory refurbished and restored U.S. WWII M1 carbines and other various civilian owned U.S. military rifles. Their services were offered to customers but also done on rifles they then sold. Their business expanded over time to include the manufacturing of various U.S. military style rifles. To include newly manufactured M1 carbines.

Prior to manufacturing their own carbines, from April 2004 thru mid 2005 they offered customers the option of having their carbines converted to MMJ 5.7mm Spitfire. Refurbished carbines they sold could be purchased in .30 carbine or MMJ 5.7mm.

Military carbines they refurbished/restored retained their original markings. It's not known what markings they added to those converted to MMJ 5.7mm.

Additional Resources

In February 2016, the American Rifleman Television program "This Old Rifle" aired a segment devoted to Melvin Johnson and his Johnson 5.7mm Spitfire carbine. The segment can be viewed on YouTube by clicking here.

Ed Johnson hosted an online 5.7mm Club from 2004 to 2005 or 2006. His web pages have been archived by the Internet Archives and can be viewed here.

The website Melvin Johnson's Rifles is devoted to Melvin Johnson and his inventions. It includes a discussion forum for the MMJ 5.7mm with posts by Ed Johnson.