The 5.7 OG

Mel Johnson holding a sporting Spitfire with his rifles and MGs displayed.

Mel Johnson holding a sporting Spitfire with his rifles and MGs displayed.

Long before FN differentiated their small .22 caliber centerfire pistol round by calling it the 5.7, another 5.7 launched in a big media splash and went nowhere — even though it’s father was one of the most distinguished firearms designers of the 20th Century.

The 5.7 Original Gangsta round is often called the 5.7 Spitfire, although its official name was actually the 5.7 MMJ, after the initials of its inventor: Melvin M. Johnson of Johnson Rifle and LMG fame. Johnson began working on a 5.7 x 33 necked version of the US .30 Carbine cartridge in 1961, and introduced the cartridge in his own M1 Carbine version, the 5.7 Spitfire, in 1963. While he always intended the round to be a light, handy, high-velocity carbine round, he did round development in a bolt-action with a custom Sako barrel, achieving MOA accuracy. In the Spitfire carbine, 3″ groups at 100 yards was more standard, but Johnson did make a 2.25″ 5 shot group in 5 seconds from the carbine once, in 1962.

He had initially hoped for 3,000 fps but…

… this raises the pressures over the 40,000 PSI mark (.30 carbine standard) which, as Johnson says, “Is not so good for the M1 carbine extractor.”1

57 vs 30 carbine ammoyFinal performance was about 2,800 fps with a 40-grain full metal jacket bullet.

The Spitfire wasn’t just a rebarreled carbine. Rakusan noted that…

The carbine itself undergoes considerable change to accept this new cartridge. The barrel is relined and rechambered. The gas port is altered, giving twice the operating gas compression ratio of the original .30 carbine and about 20% more power in the driving spring, this plus cartridge design assuring positive feeding. With the 18″ barrel (Johnson also has a military version with a 12″ barrel) the overall length of the new carving is 35″, 27 1/2″ with the stock folded, 1 1/2″ longer than the requirements of the Federal Firearms Act. This short, handy length is achieved by a folding wire stock which also acts as an optional fore-end grip.

In 1964, Johnson would sell you a Spitfire from his New Haven business address for $130, or convert your M1 Carbine for $73. In addition, a shorty military/NFA version was available which, with the folding stock, was a mere 21″ long folded thanks to a 12″ barrel. In addition to the military Spitfires, some were finely finished sporting arms (NRA image below):


While most modern articles about the 5.7 MMJ and 5.7 Spitfire seem to talk it up as a military gun, the 1964 Shotgun News article stresses sporting applications: “short-range varmint hunting.”

Mel Johnson writes that he was impressed by George Lindsay’s remarks in “The Hornet’s Big Enough,” published in the 17th edition of the Gun Digest, which stated, “Even out West, fences are going up. People are closing in– and somebody is sitting on my rock.”

For too many varmint hunters the days of wide open ranges are gone, and most of the hunting must be done in semi- populated areas. Here is where the 5.7 spitfire will shine– remember, it was designed primarily as a short-to-medium-range varminter.3

Johnson was still promoting the Spitfire and seeking investors when he passed away of an unexpected heart attack on a business trip to Boston. He was 55 years old, and without him, the light went out of the project, although family tried to continue it. Periodically someone tries to resurrect the project, notably IAI in the early 90s.

The 5.7 Spitfire was tested informally by SF in Vietnam (where some carried carbines because that’s what most of their CIDG carried). No one really knows how many Spirfires were made and converted; they’re rare today, but seem to draw little collector interest, perhaps because of the wildcat round. Making the ammo is not as onerous as people think, and custom-loaded (and 5.7 Johnson headstamped) ammo is available, at a price. A Spitfire would be a nice addition to a Johnson collection.


Canfield, Bruce N. (with Robert  L. Lamoureaux and Edward R. Johnson). Johnson Rifles and Machine Guns: The Story of Melvin Maynard Johnson, Jr., and His Guns. Lincoln, RI: Adrew Mowbray Publishers, 2002.

Rakusan, J. 5.7 Spitfire, in Amber, John T. (Ed.). Gun Digest, 1964. Chicago: Follett Publishing Company, 1964. p. 166.


  1. Rakusan, J. 5.7 Spitfire, in Amber, John T. (Ed.). Gun Digest, 1964. Chicago: Follett Publishing Company, 1964. p. 166.
  2. Ibid. 
  3. Ibid. 

28 thoughts on “The 5.7 OG

  1. Tom Stone

    I saw a few of these at the range (Chabot) in the 1960’s
    They were the sporter version and very attractive little rifles.
    The report was quite sharp from an 18″ barrel.

  2. Aesop

    Given the historical provenance, perhaps FN could have a chat with Inland about a new 5.7 project gun…?
    Especially since one is more likely to find a case of 5.7 in the wild than .22LR, anytime this side of the 47th president.

    Nah. That would require something like sense and perspicacity from actual firearms manufactories, which is like wishing for rain in the Sahara, and occurs about as often.

  3. Jew with a Gun

    Slight typo… you referenced IMI as trying to bring it back, but linked to IAI. IAI is not the same as IMI, and their M1 carbines were not Israeli-made.

    Now, that said, IMI did try to resurrect the .30 M1 carbine _cartridge_ with the Magal derivative of the Galil MAR. Unfortunately, the Magal was not reliable, and was discontinued pretty quickly. (It presumably would have functioned somewhat better with the higher-pressure 5.7MMJ cartridge, so maybe Johnson was just ahead of his time.)

  4. DSM

    2800fps isn’t bad at all for a .224 bullet in a varmint situation. As a youngster I used to dispatch the groundhogs in the homestead’s veggie patch with my old Inland carbine. The slow 110gr ball rounds would knock the snot out of them at 50yds. That little 40gr slug wouldn’t have much drop to speak of right out to about 150-175yds so even the skittish pests could get a little action.

  5. Ken

    I have a .218 Bee which I think has a similar powder capacity. It is a wonderful little cartridge, quiet, powerful enough for most things, and cheap and easy to load for. People are missing out when they skip over these little jewels. The .22 spitfire would be the tits in a little magazine fed bolt action built just for it.

  6. John M.

    I was going to post a snarky comment about the world needing another cartridge with the ballistics of .22 Magnum, but then I looked it up, and good gravy, 40 gr. at 2800 fps is humming. Per Wikipedia, the .22 Mag launches a 40 grain pill at just over 2000 fps, and 5.7×28 only lists up to 31 grains at about 2300. This little bugger seems to be in its own little category.

    -John M.

    1. LSWCHP

      This is .22 Hornet turf. I have a beautiful little Browning A-bolt Micro Hunter chambered for the Hornet, and I can get identical performance to the Spitfire. I would swap it for a Spitfire though, due to the difficulties of reloading for the Hornet and getting good accuracy. I love the look of this cartridge.

  7. Loren

    So it’s a 22 Hornet (or close enough) – 43 gr @ 2714 in my single shot H&R. Nice little gun.

  8. DSM

    I need to stop thinking about this because all I need is an eccentric round to reload for. But, that little beat up Inland carbine was my first real rifle so I’ve got a soft spot in my heart for them and a 5.7 would be a unique shooter. Forming brass is tedious but still quite rewarding and I’d bet I could get explosive performance from some hand swaged 22 Shorts turned bullet jackets. Ok, just for giggles let me look into the dies, ya know, for gee whiz….

  9. ihc53

    I’ve always thought an M1 carbine chambered in 5.7mm FN would be a neat little rifle.

    1. Claypigeonshooter

      I agree, but according to Wikipedia chamber pressure is about 50,000 PSI which is much higher than 30 carbine which is about 12,000 PSI less so a beefier receiver might be needed.

      1. Hognose Post author

        In the NRA video that ran at 0600 today (i.e. 24 hours after this post we’re commenting on), Martin K.A. Morgan says that Johnson made some of his own carbine receivers.

        The 1964 Gun Digest article indicates that the original 3000 fps loading (which Johnson advertised) had to be downloaded because its chamber pressure was >40,000, and that SAAMI limit for .30 carbine was 30,000, I believe. I should just scan and post the article because it has some good pictures of Johnson.

      2. archy

        ***I agree, but according to Wikipedia chamber pressure is about 50,000 PSI which is much higher than 30 carbine which is about 12,000 PSI less so a beefier receiver might be needed.***

        You’ll also need a MUCH stouter op-rod side bolt lug; even hot or heavy bullet .30 carbine loads will destroy GI carbine bolts, particularly the early flat ones. And as Mr. Johnson noted, an extractor redesign will be called for as well.

        There were successful commercial 9mm carbine versions and a commercially offered 9mm parabellum conversion service offered for police departments that used the things but were finding that free/cheap GI ball ammo had dried up. And Down South of the Border, there were conversions to 9mm Largo, which ran a little hotter than 9 para, but not much. I always wondered how a 7,62×25 Mauser caliber carbine would have fared.

        Happily, there’s now very credible JHP ammo around for the .30 M1, and it can be used as it was meant to be. Which is what it does best.

  10. 6pounder

    Great article. I had almost forgotten about this one. It’s a shame it didn’t catch on more. Reforming brass for this and a lot of other rounds isn’t hard. It’s actually a very interesting hobby alongside reloading. The most critical part is proper annealing and knowing what stage to do it. Carbine brass is certainly easy to find.

  11. Michael Bane

    GREAT ARTICLE, guys! We’re doing a GUN STORIES WITH JOE MANTEGNA on little speedball .22 centerfires, sort of built around the .22 TCM. Once I got into it there was a fascinating story, starting with the Velo Dogs and going through a whole series of cartridges that almost worked. Of course my producing partner looked at the script and said, “Are we doing the whole season on obscure .22 centerfire cartridges?” Sigh…

    I love the Charlie Askins “cheater” cartridge, the .221 Askins!

    Michael B

    1. Hognose Post author

      There’s sure a lot of them… .219 Bee, 221 Zipper… I remember in the sixties everybody had a favorite and nobody ever settled on just one.

  12. Daniel E. Watters

    Mel Johnson tried to interest ARPA in the 5.7mm Spitfire conversions prior to its commercial release, but was shot down by Deputy Director William H. Godel. Godel had been far more receptive when it came to the ArmaLite AR-15 just a few months earlier.

    One thing that gets glossed over regarding ARPA’s Project Agile evaluation of the AR-15 is the number of folks involved in the decision were later accused of influence peddling and other corrupt activities. Godel was arrested by the FBI in August 1964 in relationship to an embezzling scheme related to Project Agile. Forced out of ARPA, Godel jumped into a consulting position at Cadillac Gage. However, he would resign this position in December 1964 after he was indicted. Godel would ultimately be convicted.

    Another Project Agile alum, Col. Richard Hallock, was accused of “triple dipping” in his post-retirement consultancies with the US DOD, the Govt. of Iran, and US defense contractors during the 1970s. The DOD hired him to keep the Iranians from getting fleeced by the defense contractors, but then the Iranians hired him to consult on which weapons to buy. This allowed Hallock to then act as a gatekeeper for his own clients in the defense industry.

  13. Daniel E. Watters

    BTW: Guns Magazine reviewed the Spitfire in its March 1963 issue.

    The April 1963 issue features a full page advertisement for the Spitfire.

    The November 1964 issue carries a smaller advertisement featuring the new Deluxe Sporter Model.

    The June 1966 issue has a follow-on review, covering the Deluxe Sporter Model.

  14. cm smith

    Two other oddities: 1960’s gun magazine articles by James Mason on converting carbines to .30 and 9 mm wildcats on the 7.92 Kurtz dimensions using 7.62×51 and .30-06 brass. I think I’ve seen another on a straight 7.92 K conversion, but I’m not finding it at the moment.

    January, 1966 Guns & Ammo and December, 1969 Guns magazine.

    1. Daniel E. Watters

      Many years ago I assembled an article about known and possible cartridge conversion for the M1 carbine. It desperately needs updating, but it will give folks a place to start.

      Gun World printed a huge number of articles on customizing and wildcatting the M1 carbine soon after the DCM started selling them. These articles were so popular that they even assembled a small booklet for purchase.

      Dan Dwyer of Group Gripper fame was responsible for several of the Kurzpatrone wildcat conversions.

      A Shooting Times reader once pointed out that the carbine could be converted to .221 Fireball, but you had to use projectiles with short ogives. This also means that other Fireball-based cartidges could be used in a similar fashion. How about a short-loaded .300 Blackout using pistol projectiles? The .17 Fireball might also work.

      1. archy

        ***A Shooting Times reader once pointed out that the carbine could be converted to .221 Fireball, but you had to use projectiles with short ogives.***

        That’s one approach. The other is to squash a shotgun pellet [#4, IIRC] between two .224 gas checks, providing a very light projectile that sort of resembles an aspirin tablet, then loaded flush with the case mouth. They won’t feed through some magazine designs, but if you want a really high-velocity short-range load up the spout that leaves very little chance of overpenetration it’s one interesting answer. It works pretty well, with a .30 Springfield or M1917 as well, using .30 gas checks and a O, OO or SG buckshot pellet, those I’ve chronographed and 4000 fps neighborhoods are frequent. A corrugated cardboard box hit with one has a neat little bore-diameter hole on the entrance side, and the opposite side appears to have been hit with a .410 shotgun.

        George Nonte taught me this one.

  15. archy

    ***Many years ago I assembled an article about known and possible cartridge conversion for the M1 carbine. It desperately needs updating, but it will give folks a place to start.***

    You overlooked at least one: the St Louis-area gunsmith who converted .30 carbines circa 1963-’65, at the time available from the DCM [became the CMP, noobies!] for $20 and shipping, each, into .22 Long Rifle semiauto carbines. If I recall correctly, his conversion ran $25.00, but the similar size and feel of Ruger’s then-new 10-22 and its reliable rotary magazine pretty well pulled the wind out of the sails of that project.

    I believe it was done by the same fella who did the conversions of former French Modèle 1935 A and Modèle 1935 S 7.65mm Longue cal. *Petter pistols,* also available in those days in the $25-$35 range, and fairly popular until the ancient WWI surplus .30 Pedersen Device ammo most folks back then ran in them ran out. But as I recall, cut-down .30 carbine cases could also be used, and that may have been where the idea came from.

    There was all sorts of neat gun butchery going on back then….

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