Gabbet-Fairfax Mars Automatic Pistol

The Mars pistol was a development of the turn of the century that would really be more at home in a Jules Verne novel (I would suggest the title “One Thousand Footpounds in a Handgun”) than in the real world. It was a massive handgun, ridiculously powerful, and marvelously complex. It lasted only for a short time, with the first production prototype made by Webley in 1898 and production ceasing by 1907.

Mars Automatic Pistol
Mars Automatic Pistol (click to enlarge)

To put the gun’s physical size in context, consider the numerical data. The Mars is 25% heavier and 30% larger than the Colt 1911, and fires a very similar projectile at 50% higher velocity. Its closest comparison today is the LAR Grizzly in .45 Winchester Magnum.

Mars compared to other pistols in size and weight

Mars pistol size
This is a standard Mars, chambered for the 8.5mm Mars cartridge (click to enlarge)


The Mars is one of the few long-recoil action firearms designed and built, and this choice of action contributes to its complexity. Hugh Gabbett-Fairfax, its inventor, was dedicated to the long-recoil system because it offered a high margin of safety for his very powerful cartridge. The idea of a long recoil system is that the bolt and barrel remain locked together as the whole system recoils backwards, and only unlock when fully rearward (as opposed to short recoil, where the two parts unlock while the bolt is still moving backwards). The long locked time means that the bullet will have left the barrel and pressure will have dropped a great deal before the system opens, thus protecting the shooter.

It is worth comparing the Mars to the only reasonably successful long recoil pistol, which was the Frommer 1912. In the Frommer, bolt and barrel travel back together, and the bolt is held at it rearward position while the barrel returns forwards. The empty case is ejected as the barrel pulls off it, and when the barrel is fully home is trips a release to allow the bolt to come forward, stripping a new cartridge from the magazine as it does so. The Mars prototypes initially functioned this way (including the use of a rotating bolt, with 4 lugs in the case of the Mars), but had reliability problems. The travel distance of the moving parts (the Frommer bolt and barrel travel about an inch, compared to 3-4 inches on the Mars) combined with the significant recoil of firing tended to bounce things around and led to feeding failures. The solution was twofold. First, the normal magazine was replaced by a cartridge elevator which would pull a round backwards out of the magazine during recoil and then lift is up into the path of the bolt. Secondly, the automatic bolt release was replaced by a mechanism which held the bolt open until the shooter released the trigger.

So,if one was to press the trigger and hold it back, the Mars would fire and lock open with a new cartridge lifted and ready for chambering, but the bolt would not be released to slam forward and lock until the trigger was released. This led to one of the perennial complaints about the gun in military trials; it had a very heavy trigger pull. In addition, this mechanism was spring loaded until late in the production run, and it was possible for the bolt to jump over the catch and follow the barrel home, which was responsible for many of the feeding problems encountered in testing. The mechanism was progressively improved, and by the final few guns made it was made wholly of positive mechanical cams and the problem was eliminated.


The first Mars pistol was made by Webley & Scott, one of the foremost revolver manufacturers in England at the time. Automatic pistols from the mainland (Borchardt and Bergmann, among others) were showing popularity, and Webley wanted to get its foot in the door. They contracted to build prototypes of the first Mars design in 1898, but the collaboration would not last. By the time Gabbett-Fairfax filed his 1900 patent that became the design for the standard Mars pistol, he and Webley had gone separate ways. The reason is a bit unclear, but likely relates to Webley trying to change the design to make it more commercially feasible – something Gabbett-Fairfax would have done well to cooperate with. Webley was also working on the Webley-Fosbery automatic revolver at this time, but it and the Mars were seen as complementary products and not direct competitors (in an 1899 letter published in Arms & Explosives magazine, Gabbett-Fairfax described the Webley-Fosbery as “excellent”).

Serial production began in 1901 under Gabbett-Fairfax’s direction, and approximately 56 pistols were produced in several different calibers. The first Webley gun had been chambered for the ,360 Mars, and this cartridge continued to be used. It was a .36/9mm bottlenecked design with a 160-grain bullet fired at a very impressive 1640fps. An 8.5mm version was also produced for military trials in France (140 grain bullet at 1750fps), and a .45 caliber straight walled cartridge was also developed for British military trials (220 grain at 1250fps). A short .45 cartridge was also developed and saw very limited use, as a response to military complains over the gun’s excessive recoil.

Mars pistol cartridges
Mars pistol cartridges: from left to right, .45 Short Mars, .45 Long Mars, .360 Mars, and 8.5mm Mars (aka .335 Mars)

The pistols made during this time were being revised on a continual basis, and no two are exactly alike. Parts interchangeability is very limited, even between guns with very close serial numbers. Changes included incremental modifications to the firing mechanism, magazine parts, markings, and details like the lightening hole in the frame just above and in front of the trigger guard.

By the end of 1903, it became clear that no military contracts were going to be won, and Gabbett-Fairfax (who had been financing the whole project with personal loans) was hopelessly bankrupt. His patents were taken over by a consortium of his creditors under the name of the Mars Automatic Pistol Syndicate in an effort to revive the gun and recoup their investments. In late 1905 Clement Brown (formerly Gabbett-Fairfax’s shop manager) filed a patent for several improvements to the design. The Syndicate subcontracted manufacture out to a number of local Birmingham gunsmiths and in conjunction with remaining stocks of parts they attempted to market the improved gun in 1906. Their efforts failed completely, and by 1907 the effort was given up and the next year the Syndicate was also bankrupt, and dissolved.

Commercial Sales

Despite production of probably around 80 pistols, it appears that none were ever sold commercially. Britain’s Proof Act of 1868 required all commercially sold guns to be proof tests by an independent house, and this regulation was strictly enforced. Gabbett-Fairfax’s works were located very near to the Birmingham Proof House, and yet none of the Mars pistols known to exist today have any proof marks. A few were very likely given as gifts, but it would be extremely unlikely that any sale could have taken place without the Proof Master making a big stink about it.

Hugh Gabbett-Fairfax
Hugh Gabbett-Fairfax

Military Trials

Gabbett-Fairfax’s hopes for the Mars pistol were centered entirely upon military contracts, and the military trials of his pistol reveal many of its strengths and flaws. Between 1901 and 1903, he took the Mars to no less than eight demonstrations and military trials, and was given more chances to prove his design than most inventors. In general, military examiners held the Mar’s accuracy in high regard, and there was no doubting its man-stopping capacity. The objections were to its complexity, weight, recoil, hard trigger pull (10 pounds, according to one trial report), tendency to eject cases directly back into the firer’s face, and failures to feed.

Some of the feeding failures were due to the afore-mentioned problems with the bolt catch malfunctioning, and with shooters releasing the trigger too early. Other problems were often encountered with ammunition, including underpowered loads, insufficient crimps leading to bullets telescoping into cases, and uneven rim thickness. Through the several years of testing with the different branches of the British military, Gabbett-Fairfax had plenty of opportunities to revise the pistol to satisfy the complaints made about it – which were pretty much the same in every test. He failed to do so, though, and one really can’t blame the military for not giving him enough chances.

The final conclusion of the War Office Small Arms Committee described the Mars as: “A very powerful pistol. Its accuracy, penetration, and no doubt its stopping power, are good. It is, however, complicated, in its present form, would be difficult to clean, and is heavy. A great deal of firing has been carried out with it. The mechanism did not always work well, and the recoil was complained of. Much difficulty was experienced in obtaining satisfactory ammunition, and this was no doubt often the cause of defective working of the mechanism.” Ultimately, the committee concluded that automatic pistols were simply not well enough developed to merit military use at the present time.


This particular Mars pistol is chambered for 8.5mm, and was sent to France for military trials (download the gallery in high resolution)

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Mars Pistol Manual (English, 1902)
Mars Pistol Manual (English, 1902)


US Patent 684,055 (H. W. Gabbett-Fairfax, “Automatic Firearm”, October 15, 1900)

British Patent 25,656 (Clement Brown, “Improvements relating to the Breech Mechanism of Automatic Fire Arms”, December 9, 1905)


Sturgess, Dr. Geoffrey L. “The Gabbett-Fairfax Mars Pistols” Journal of the Historical Breechloading Small Arms Association, Volume 2, Number 8.

Stewart, James B. “The Magnificant Mars” GUNS Magazine, July 1974


  1. Thanks for posting such a fresh and complete article.

    I’ve a file somewhere of Gabbett-Fairfax patents, ranging from a machine for shelling Brazil nuts, through various artillery buffers and automatic weapon mechanisms full of racks and gears, to the “Mars”.

    The range and nature of the patents suggest that he was something of an eccentric dreamer, in contrast to the unbelievably practical John Moses Browning, and Mauser Brothers, who’d grown up in their Father’s shops, and designed guns to be made and sold.

    In terms of “ideal types” I place Gabbtet-Fairfax into the same category as C.H.A.F.L. Ross (of straight pull Canadian Rifle and hot .280 cartridge infamy) and that notorious troll of 1900’s letters to the editor pages, Charles Newton.

    Many thanks too, for the referencing 🙂
    I was un aware of the Historical Breechloading Small Arms Association, or of the Clement Brown Patent.

    Authors failing to cite sources has cost me years in terms of learning about guns, your blog is one of the pleasant exceptions to that bad habit.

  2. I had read that the Mars was the first, albeit unsucessfull, pistol to have a box magazine which was inserted into the grip. Commonplace now but the first none the less.

  3. I often thought the recoil complaints about the Gabbet-Fairifax were due to the high bore axis, relative to the grip. The one I saw had a bore line higher than the largest S&W N Frame revolver.

  4. were there ever any carbine version made (select fire with detachable stock )

    i would love to see a slo mo video of this gun firing but that’s just not going to happen

    • Some of the period documents talk about detachable shoulder stocks, but I’m not aware of any photos of them, much less a surviving example. If they were made, I believe they would have been semiauto only – the feed issues inherent to the design would have made fully automatic function very unreliable.

  5. A well-written article about a rare and intriguing firearm and its place in history. The original ammunition for the Mars pistol would obviously be virtually impossible to come by, and new rounds would have to be hand-made in small batches to the original design drawings. Are there any plans afoot to do this so that a live-firing exercise can be carried out?

    Keith continues to amaze me with his in-depth knowledge, particularly when it comes to patent research.

    • Thanks, Earl. I wouldn’t completely rule anything out, but I don’t have any firing opportunities for a Mars on the visible horizon. You never know what can turn up, though…and I would be totally gung-ho to put a few rounds through one on camera. 🙂

  6. Worth tracking down a copy of RK Wilson’s “Textbook of Automatic Pistols” for an amusing first-hand account of shooting the .360 Mars. Plenty of other obscure information on obscure weapons in there too.

  7. Thanks for this very informative post.

    It seems and confirmed by its manual that, loading through an elevator into a
    barrel located over the magazine had choosen especially to get longest barrel
    to obtain highest muzzle velocity as burning the highest of volume of gun powder
    possible to get biggest stopping power in a pistol of carriable size.

    Though having very attractive human engineering points like magazine catch,
    application of the same concept througout the pistol work out is unfortunatelly
    at the negative side. The barrel axis is too high and most of the mass recoils
    rearwardly beyond the holding hand as multifolding the existing muzzle rise.
    Besides, hammer is also very prone to bite or punch the holding handwrist. Using
    an armoured gloove should be needed. It would be the cause of reluctancy of users
    at a time “Not being eager to fire that pistol twice”.

  8. If I recall correctly, according to Boothroyd’s “The Handgun” the testers at a Royal Navy shore establishment were actually AFRAID of the gun after firing it a few times. I imagine that someone accustomed to the .476 and .455 revolver cartridges would be brought up short by the “Mars” rounds.

  9. I’ve been slowly digesting the new Mars info which you’ve given us.

    Clearly Gabbett-Fairfax was something of an obsessive personality, clinging to his artillery style multi lug rotating bolt, long recoil operation and overly long barrel, and the problems inherrent with those.

    a better engineer would have searched for simpler ways around the problems of an auto loading pistol, and along the way, realized that the ballistic performance which G-F sought, might be fun on a range or game shooting, but does not make for a practical military weapon (heavy to carry, to much noise, too slow to get on target, and too slow to recover for follow up shots).

    A better businessman would not have ended up so pathetically in debt…

    Despite those criticisms, some of the problems which Gabbett-Fairfax tried to solve are still relevant.

    Better engineers than G-F have made commercially successful long recoil guns; the astounding example being J M Browning’s long recoil shotgun (US Pat 659,507), over the years this was manufactured by Remington, Savage, FN, Browning, and is still manufactured by Franchi as the 48AL, almost 113 years since Browning applied for his US patent.

    A feeder tube separate from direct magazine feed is a central part of the current Russian assault rifle (Nikonov, US Pat 6,516,700 see fig 6 for a schematic representation), allowing a rapid second shot while the barrel and action recoil within the cradle of the stock and receiver housing. Nikonov’s rifle is notable for many of the opposite reasons that the Mars is notable;

    most especially for minimal recoil impulse!


  10. The current paradigm for self loading pistols involves variations of Browning’s combined slide and breech bolt (see the three consecutive US patents, 580, 923, 4 and 5 (the slide is 580, 924) for an amusing insight into some of the other thoughts competing for space in Browning’s mind and on his work bench!).

    The Browning slide works well with full size pistols, such as the 1911 and Browning’s later GP35.

    The 1911 derivatives by Coonan and Wildey, demonstrate that (for anyone who wants it) magnum performance can be achieved in a handgun with similar weight to the Mars, but far simpler mechanics, and infinitely better ergonomics, using Browning’s ideas.

    Where the Browning slide becomes more problematic, is with ultra compact pistols for concealed carry.

    A quick look at any of the popular manufacturers sites will show pistols with a greater length of slide behind the breech end of the barrel than in front of it, because of the need to keep the magazine covered and the top round depressed.

    Although Gabbett-Fairfax’ realization of a pistol with its breech aligned behind the front of the grip, is totally impractical…
    Similar proportioning would allow a concealed carry pistol, either much shorter than those with the Browning slide for the same length barrel, or of similar length but with a much longer barrel.

    The difficult part would be to achieve that together with a low bore centre line.

    Pistols which actually do achieve that, are the Hino Komura (which Ian has recently covered), which operated from the blow forward equivalent of an open bolt (US Pat 886,211)

    The Schwarzlose blow forward pocket pistol (us pat 918,380) which was actually a modest commercial success,

    and the Scwarzlos’ .45 ACP current equivalent, the manual repeating Simmerling LM4, invented by Lichtman ( US Pat 4,155,187 ), and manufactured by American Derringer (or at least available from them).

    Lichtman’s patent contains the suggestion of using a Williams type floating chamber to achieve semi auto operation. Unfortunately, the firer’s hand would already be taking the full recoil of the round through the pistol’s standing breech, to add a floating chamber would add to that recoil as the barrel/slide would be accelerated forward, with the equal but opposite reaction being against the standing breech and the firer’s hand.

    Cont over the next few days.

  11. Hi, stumbled upon this article after I read the probability broach graphic novel where the mars features prominently. I and my father want to know, what is the purpose of the hole above the trigger-guard?

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