Detroit’s Short-Lived Kimball .30 Carbine Pistol

Target Model
Combat Model

The J. Kimball Arms Company of Detroit introduced a semiauto pistol in 1955, chambered for the .30 Carbine cartridge – what better companion for the tactical uber weapon of the day, the M1 Carbine? Kimball’s pistol was styled heavily after the High Standard, and it looks good and handles well. The .30 Carbine cartridge is too powerful for a blowback pistol, however, and so Kimball needed some type of locked breech or delaying mechanism. He chose to cut an annular ring in the front of the chamber – the mouth of the brass would expand into this ring upon firing, and the force required to press it back down to the diameter of the chamber body would force the slide to remain closed long enough for pressure to drop to a safe level.

However, the system was not adequate for the cartridge. The slide velocity was high enough that the guns very quickly battered the slide stop block. The would peen and deform at first, then crack, and eventually either bend to the point that the gun would not cycle, or break off and allow the slide to come right off the back of the frame. I can’t find any documentation of anyone actually injured in this way, but that was obviously the concern. Only between 250 and 300 of the pistols were made before the company went bankrupt and closed. There had been plans to expand the line to include gun in .38 Special, .357 Magnum, and .22 Hornet, but none of those went any farther than prototypes.

57 Comments

  1. “cut an annular ring in the front of the chamber – the mouth of the brass would expand into this ring upon firing, and the force required to press it back down to the diameter of the chamber body would force the slide to remain closed long enough for pressure to drop to a safe level.”
    Similar solution was used in Mann automatic pistol firing 6,35 mm Browning (.25 Auto) cartridge: https://unblinkingeye.com/Guns/Mann/mann.html
    this cartridge did not require any delay mechanism, as it worked reliably in blow-back (pure blow-back) automatic pistol of numerous models (too many in 20th century Europe to list them all here), however such solution allowed usage of lighter breech block. Mann solution differ in that groove is not near case mouth, but in half of length, which might be clearly seen at 2nd photo from top.

  2. The annular ring wasn’t quite the whole of the delaying system. If you look closely when Ian shines the light up into the chamber, you will see a series of dark “rectangles” in the chamber walls.

    These are actually rows of fine annular grooves in the chamber, intended to “grab” the cartridge case’s brass and act as a drag on its progress backward out of the chamber. I don’t recall this system ever being attempted in another pistol.

    Whether or not it would work would largely depend on the hardness of the brass in the particular .30 carbine ammunition being used. The harder the brass, the less effective it would be.

    The Kimball was originally intended as a military sidearm, a potential replacement for the M1911 .45. Before anyone says a blowback or a .30 USC pistol in that role is a strange idea, I would point out two things.

    First, the Harrington & Richardson T3 prototype 9 x 19mm pistol of 1953 was a straight blowback, that competed with the Smith & Wesson 9 x 19mm prototype that became the Model 39.

    Second, during World War Two S&W made a limited number of Model 10 M&P revolvers in .30 USC as potential paratrooper sidearms. They were tested by the Army and rejected, not due to any weaknesses but because the blast and recoil of the .30 Carbine round in a 5-inch barreled revolver was considered too severe for troops to tolerate.

    One can only wonder what they would have thought of the Ruger Single-Six revolver in .30 Carbine, introduced two decades later. Of course, Bill Ruger was looking at the sporting market, not the military.

    In fact, the .30 Carbine round really doesn’t work too well in a pistol. Most loadings require at least 12″ of barrel to develop full velocity due to the burning/pressure curve of the powders used, which considering they are intended for use in a rifle with a short-stroke piston, gas-operated system makes perfect sense.

    Ruger & Co.’s genius is well shown by the fact that they could make a similar system in the Mini-14 family work with cartridges ranging from 5.56 x 45mm to 7.62 x 39mm, intended for entirely different types of gas systems (Ljungman type and Garand-type, respectively).

    Putting the .30 Carbine round into a self-loading pistol can be done (see “Automag III”), but generally it isn’t worth the effort. By the time you’ve gone to the trouble of developing loads that work efficiently in the shorter barrel, with tolerable levels of blast and flash, what you’ve got is basically a rimless .32-20 WCF. This is also true of revolvers in .30 USC.

    For a pistol in this caliber/power class today, I’d suggest a Ruger Single-Six in .327 Federal. A cartridge designed from the outset for use in a handgun.

    cheers

    eon

    • “5.56 x 45mm to 7.62 x 39mm, intended for entirely different types of gas systems (Ljungman type and Garand-type, respectively).”
      Wait, what mean Garand-type? Long-stroke gas piston as opposition to short-stroke gas piston? If so I see nothing genius in Ruger & Co. action, as weapon which was chambered for 7,62×39 cartridge AND is short-stroke gas piston was created (and passed state trials) by Simonov, namely SKS, yet back in 1945.

      • The Kalashnikov action is basically a Garand action with the gas piston above the barrel rather than below it. And its safety/selector system was essentially copied from the Remington Model 8 sporting rifle.

        There is still debate as to the origin of its cartridge, which may originally have been a German design from the Polte firm. Kalashnikov stated that he did not design the cartridge, he was given the specifications and told to design a rifle to use it.

        There really isn’t anything original in the Avtomat Kalashnikov obr. 1947. It is, nevertheless, a good synthesis of proven principles.

        As for the Simonov short-stoke piston, Winchester’s system in the U.S. M1 carbine predated it by five years (1940).

        cheers

        eon

        • “which may originally have been a German design from the Polte firm”
          Not. While development of this cartridge was sparked by examining of captured MKb.42(H) it is own design.

        • Long Stroke piston gas operation refers actions working with a longer gas tube than the round used and carrying gas push through all over the stroke lenght without exhaust holes like M1 Garand. They usually carry the gas pistons at the front half of the barrel and very near to the muzzle and rarely have gas exhaust holes since there would be no bullet plug alongside the cycling to rise the inside pressure to fasten the action mechanism. AK47 should be accepted as short stroke gas piston operated since the gas push inside the tube is exhausted after a short travel backward and gas piston continues its rearward travel within the guiding tube seeming like the contuniation of gas cylinder. The location of gas mechanism is so arranged that, at starting of the gas inlet, the projectile inside the barrel still acts as a plug and if the gas exhausting would not occured, the pressure inside gas device would rise to the dangerous level as to harm the action.

          • Gas pressure acting on piston does not last for very long, only the bullet distance from gas canal to muzzle. For that time the piston barely manages to get moving. Whole action may last 3-5 millisecond due to action inertia. Actually, the bullet does not stay in barrel much past 2ms; after that pressure drops to zero. Take muzzle velocity, divide by half and divide that by length of barrel; lets see what you get.

    • “Putting the .30 Carbine round into a self-loading pistol can be done (see “Automag III”), but generally it isn’t worth the effort.”
      What make Kimball automatic pistol interesting is that he managed to put magazine into grip, without making it excessively long, something which AutoMag apparently failed. BTW: Why Automag sequence starts from II rather than I?

      “For a pistol in this caliber/power class today, I’d suggest a Ruger Single-Six in .327 Federal. A cartridge designed from the outset for use in a handgun.”
      7.62×25 model 1930 (sometimes named 7.62×25 Tokarev) seems also feasible. Sadly, no new automatic pistols for that caliber was introduced recently, thus only readily available automatic pistols designed for that cartridge are Czechoslovak vz. 52 and Soviet TT.

      • The relationship between Kimberley and the shop doin the metalwork ended with the stock of parts being dumped into a barrel and left outside in the shop’so compound.

        A gunshop bought the parts and at least a couple of pistols wwere assembled with barrels chambered for.30 luger

    • Having witnessed an Automag III being fired, I can attest that 30 Carbine from a pistol generate the most unpleasant blast possible.

      Another variant of annular groove is found on Russian PMM. A spiral groove was cut in the chamber to deal with +P variant of 9 Makarov.

      • ” A spiral groove was cut in the chamber to deal with +P variant of 9 Makarov.”
        There exist also codenamed ОЦ-35: http://gunrf.ru/rg_pistol_OTs35_eng.html
        it has muzzle(slide)-brake-compensator, which allows to fire PMM cartridge.
        Existing PM (Makarov) could be upgrade to become ОЦ-35. It has no other differences from Makarov beyond this device.
        Overall length is 185 mm, muzzle velocity 315 m/s (with PM cartridge) or 425 m/s (with PMM cartridge)

    • Your comments are correct, but i’ll Bet you a good meal that if they come out with a reasonably priced .30 carbine A la automag design, all the millions of M1 Carbine owners will seriously consider getting one.

  3. Maybe the best solution to this problem is the basic Browning lock, more specifically the FN Hi-Power variation. I could be wrong.

    • By proper design and metallurgy, the Browning locking system has accommodated some fairly high-pressure rounds, such as the .357 and .41 Magnum (Coonan), and the .44 Magnum and .45 Winchester Magnum (LAR Grizzly).

      The Magnum revolver rounds operate at a SAAMI maximum pressure of 35,000 to 36,000 PSI, while the .45 Win. Mag and .30 Carbine both operate at 40,000 PSI maximum.

      So yes, a Browning locking system should be able to handle .30 Carbine. The question is, is it worth the effort?

      cheers

      eon

      • I suppose a small “pistol carbine” could be made with the Browning lock, but I imagine something more like the Simonov AG-043 would be better… I could be wrong.

        • “(…)Simonov AG-043 would be better…(…)”
          For?
          Automatic pistol is automatic pistol and avtomat is avtomat, they should never be confused.

        • Though, on the other hand fixed barrel approach of delayed-blowback solution should allow to add easily flash-hider or muzzle brake or other muzzle device even of big size (mass), without hampering reliability – in case of short-recoil/tilt it is not easy as it will affect balance of whole mechanism.
          It is quite interesting that Kimball automatic pistol lack any muzzle device, despite .30 Carbine is said to give vicious flash when fired from barrel of given length. He should be aware of existence of flash-hiders if he had contact with BAR M1918.

          • Kimball barrel is not fixed. It is supposed that the sticked empty case as swollen inside the annular ring at instant of discharge, would drag it backward with propped breechbolt until the highest pressure drops. The barrel and bolt act as quasi locked for a short distance and as the former stops, the bolt continues its rearward travel with gained momentum and largely with excess amount of pressure as dragging the empty case out from the barrel. If it were any barrel attachement, the gun would not cycle as supposed. Both barrel and bolt return their foretmost positions by the force of their return springs. Barrel’s is inside the tube seeming under its chamber section. Pistol is supposed to work in short recoil manner without a locking device.

          • “Pistol is supposed to work in short recoil manner without a locking device.”
            Thanks for explanation, now I see some parallel with primer-actuated
            http://guns.wikia.com/wiki/Garand_Model_1919
            as both promise simpler and lets call it more elegant way that short-recoil/tilt (no need for locking element) or gas-operated (no need for gas system), both also are very dependent on cartridge used, so potentially dangerous/unreliable to use – if “good” (will work) and “bad” (will not work) cartridges are visually not differentiable, then chance that something will go wrong are high.

        • I looked at that Automag II; it looks like much simplified concept over the previous (which somehow resembles Schwarzlose rotary action pistol). Just wondering, how long that locking interface will last before head space will stretch. Browning action is meant for pistol ammunition. This is kind on cheesy end, but I may be off.

          • Wait, do you mean Automag II or Automag III?
            II is utilized simple blowback action with radially grooved chamber (to resist and delay initial extraction when pressure in the barrel still high)
            thus it is not locked at all and anyway cartridge used (.22 WMR) head-space on rim.

        • Why I am sayin it, regarding head space change? It is because barrel cannot be hardened (in relative sense) in order to remain ductile. Action parts on rifles are typically carburized and hardened.

  4. lf noticed the tube under the chamber section of barrel, it is the housing of powerfull return spring of free floating barrel during the dicharge as carrying the sticked empty case as if the barrel being locked with the breechbolt at instant when the highest pressure exists. The annular ring and recktangular cuts (Thanks Eon) are the parts of approach to keep the empty case within the fully supported barrel during this supposed rearward travel.

    • Ian’s video also shows the backward barrel travel recess at just in front of the feed ramp.(8.20-8.40 Min.). Same approach was used later, by Kel-Tec in their PMR30 .22″MRF pistol without chamber inside ring and cuts; Powerfull magnum rounds stick inside and drag the barrel for a while with slide, weak LR cartridges only push the breechbolt.

      • There is a russian 9mm mak full auto pistol called ots 33 Pernach that uses the same barrel moving backwards a bit unlocked action,
        if I understood correctly the info on it; I suppose it is to help with firing more powerful type of ammo.

          • Its crudely translated so I still dont understand if barrel moves in moment of firing or only after the slide hits it and drags it back.

            Imho, it seems to me like there is an cutout in barrel (check the crude milling marks L shaped) that mates with slide with some peg or something.
            So that when slide starts to recoil, it drags the barrel back with it for 5mm (I suppose case moves 1-2mm in max pressure). Check out how fat and beefy barrel is – also its square, not round.
            This is speculative and open for another interpretation.

            In that way you could add the barrel mass to slide and end up with less momentum and slide speed in recoil, less slide speed gives lower rate of fire.

          • This seems rather a different approach, since the barrel chamber is not descibed with dragging measures inside, to start bakcward movement together with slide. Concept looks like using big barrel mass and its return spring to dampen the violent bacward strike of slide possibly harming the receiver and spoiling the hold of aim for the foregoing shots. Besides, the barrel return spring might have also a bumper effect forwards when the slide returns home as giving another strike with collected energy of both barrel and slide return springs. lMHO.

          • “Its crudely translated so I still dont understand if barrel moves in moment of firing or only after the slide hits it and drags it back.”
            That second one: only after the slide hits it and drags it back

          • Kimball actually patented the floating barrel as a delay system

            The same blow back and barrel that is free to move backwards system is used together with a chamber inner surface that is threaded,

            On the. 38 special Colt 1911 “Gold Cup”

          • “Kimball actually patented the floating barrel as a delay system ”
            Mythic Armory query https://www.mythicarmory.com/kimball-arms-30-carbine.html lists following patents regarding this automatic pistol:
            US Patent 2,846,926 “Floating barrel action for automatic pistol”
            US Patent 2,781,697 “Trigger mechanism for a semiautomatic firearm”
            US Patent 2,870,562 “Cartridge case extractor for a firearm”

          • I would he really happy if we manage to find Pernach patent, and clear out the operating dilemmas !

          • Found some stuff from Stechkin and his co homeboys designers but sadly nothing about ots 33.

            I believe it should exist somewhere. Will keep diggin.

  5. Do I use gun-oil, or sizing lube ?
    Thanks for showing us another dead-end development in the
    history of all things bang.

    • re: Do I use gun-oil, or sizing lube ?

      That hints at an aspect of .30carb that may be lost on those unfamiliar with it. It’s not a straight-wall case. It’s slightly tapered, which is a nuisance if you have to reload it (which I have, once upon a time). Can’t use carbide dies. Must use case lube when re-sizing.

      And you probably do need to reload for use of .30carb in a handgun, because the commercial loads must be presumed to be burn-timed for carbine barrel length, and thus still burning after the projectile exits a handgun muzzle.

      The application (high energy ~.31 cal handguns) has much more suitable choices available, esp. for revolvers (e.g. the .327 Fed already mentioned).

    • There’s not a lot in there that was as dead end as the total blend of features.

      Floating barrel blowback has been used on a big name production pistol.

  6. I’ve had the chance to fire a Ruger Blackhawk (not Single Six) in .30 Carbine.

    Exciting.

    Not the recoil, per se, but the blast from even the 7.5″ barrel was not pleasant. Ear plugs are not an optional item. That said, it did handle and perform well.

    I can only imagine the muzzle blast from the short barrel of the “Combat model” Kimber.

  7. Strongarm was quicker in describing the system,thanks so I would not need to,
    shame Ian didnt know about it fully, beside the chamber ring.

    There is a patent if someone wants to know about it more, search for it.

    The designer should have come up with some effective buffer, and maybe it would have been a viable design.
    But who knows, perhaps he tried and concluded all is a wasted effort, or ran out of funds for new parts, frames and slides,
    or in the end it was a combination of many setbacks that doomed it and shelved as another forg.weapon.

    If I remember correctly, I’ve seen on some forum, somebody stumbled on (many?) unfinished frames for this gun, and was selling them.

    Its true you get inferior ballistics with quasi rifle round out of a pistol, but logistics wise you could have unified type of ammo (every military wet dream!), and in some situations pistol is more handy and easier to conceal and operate than a rifle, especially in shtf survival situations where one could even end up losing/hiding a carbine.

    • “Its true you get inferior ballistics with quasi rifle round out of a pistol, but logistics wise you could have unified type of ammo (every military wet dream!), and in some situations pistol is more handy and easier to conceal and operate than a rifle, especially in shtf survival situations where one could even end up losing/hiding a carbine.”
      As .30 Carbine apparently is hard to put into automatic pistol, then I suggest something go-around solution – magazine-less multi-barreled pistol, it might be similar in operation to SPP-1: https://modernfirearms.net/en/handguns/handguns-en/russia-semi-automatic-pistols/spp-1m-podvodnyj-eng/
      also it should be possible to use quite long barrel and grip move forward for balance.
      Number of barrels is up to discussion – it might be 2 or 4, or maybe 3? Depending on how much mass you can accept.

  8. Welcome Storm. ln fact, related patent does not include any statement regarding chamber grooves. Besides, .30″ Carbine round with slightly tapered case, needs a !ocked breech or in other case, a movable barrel would tend to act forwards, since forwarding bullet until leaving the barrel, behaves as a plug trasmitting the gas pressure to the tube mass dragging to forward. At least a parallel sided case or case sticking chamber inside profiles are needed to stop and even act the barrel to the same direction with the unlocked breechbolt. Mr. Kimball should have realized this after his patent been granted.

  9. Also it is possible that some things are left out of patents to be like kind of trade secrets.

    I’ve seen sometimes funky stuff, for example in brasilian Uru smg patent incorrectly positioned trigger/sear on different axis pins (and all other uru patents do not even show it at all), like somebody wanted to point the wannabee copycats in wrong direction.

  10. Higly possible. But, in patent specification and drawings, pistol seems having a movable barrel close to “Long Recoil” motional gap rather than “Short Recoil” presented in real example, as if, whole delay occurance depended upon this respectable long backward barrel movement.

  11. The aesthetically very similar Catron pistols used the entire back strap of the grip as a slide stop piece.

    They are claimed to have been tested to over 20k rounds of their proprietary reduced load 9mm

    Without a slide stop failure.

    There are several possibilities for the short life of the production Kimball slide stops

    They all appear to have been made as one batch, so material problems, heat treatment problems or simply the parts being cut with the grain of the steel running in the wrong orientation,are all possibilities.

    In Catron’s designs. The backstrap appears to function as a resilient spring

    This is a questionable feature when it is part of the actual grip in contact with the firer’s hand.

    But, introducing some resilience and buffering into the slide stop, does appear to be a possible way to increase durability

    Ultimately kimball’s several patents show lots of (too) clever thinking going into the design.

    It seems as though Kimball seriously under estimated the amount of debugging development work needed

    And he probably lacked the capital to do that work as well.

    The relationship with the machine shop that was doing the manufacturing, seems to have become acrimonious very quickly

    I’m not sure what proportions of blame storming versus un paid bills were involved.

    • Hope we’ll see a vid on them one day.
      But Ian needs to do more research if he can, now in these auction videos he presents sometimes very short info, like few sentences that can be found on every wikipedia. Hopely commentors supplement the additional knowledge

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