The Schönberger-Laumann (Steyr M1892) controversy.
For being a historically very significant firearm, one of the very earliest automatic pistols, the Schönberger-Laumann is not particularly well understood. Both internet sources and “canonical” books alike give differing reports concerning its most basic functioning.
For example, Ian V. Hogg (1926 – 2002), the notable British author of numerous books on firearms and other military equipment, described the pistol in question as having been primer actuated. “The bolt is locked by a cam surface on a forked arm; when the pistol is fired, the cap [or primer] sets back about 0.18 of an inch, imparting movement to the heavy striker before the cap is stopped by the face of the bolt. This slight movement is sufficient to cause a lug on the striker to disengage the locking cam, so leaving the bolt free to recoil…” From New Illustrated Encyclopedia of Firearms. Edward C. Ezell agrees with the above judgement and even includes a very detailed (and seemingly fabricated) description of the primer actuation process in his Handguns of the World.
Others probably fall closer to the mark when they simply describe it as a blowback action. Although I haven’t read it myself, I have heard that R. K. Wilson in his 1943 Textbook of Automatic Pistols describes the Schönberger-Laumann as a delayed blowback design, which I now believe to be correct.
So why this confusion, considering that the US patent (in any case) hasn’t been lost to history? Simply put, the patent itself is most likely the biggest source of confusion. US No. 534,894 of Feb. 26, 1895 is rather poorly written by most modern standards. Crucial details about the functioning of the bolt delay mechanism are practically hidden throughout the text and some of the wording verges on the outright cryptic. Furthermore, the supplied drawings are anything but tidy. Certain important parts are never shown separate from the assembled whole. Tiny letters meant to identify important components are strewn throughout the images and are difficult to correctly attribute. Three alternative configurations of the pistol (semi-auto, a simpler semi-auto setup and full-auto) are depicted in the drawings, some with overlaid dotted lines indicating various stages of operation, further complicating things. Additionally, Laumann simply did not have much access to a standardized method of describing automatic arms. Considering this it’s no wonder that some of his terminology is rather creative.
All of this aside, the fairly unique nature of the action itself makes it a little difficult to call a classification one way or another.
Having studied the patent intensively I feel as though I understand why Hogg assumed the action to be a primer-actuated type (one may wish to consult the supplied patent drawings and the full text of the patent in order to better follow the next section). In the first case, the US drawing of the bolt itself shows its construction to be such that the firing pin might plausibly be able to protrude so far out of the breech face while firing as to fairly impale the primer of a round rather than merely strike it. Furthermore, protrusions that are part of the firing pin itself interact with the blowback delaying components of the bolt mechanism. All of this can easily lead one to assume a primer-actuation at play. The truth of the matter, however, is that the drawings show the firing pin as being obstructed from sliding as far forward as might be imagined possible and as would be necessary for primer actuation. The text also makes it clear that as much as anything the “locking bar” (J) pushes the firing pin back after being only briefly delayed by the pin’s projection (g1)- the firing pin doesn’t itself actually have to be pushed back prior to J rising out of the corresponding notch (h1) in the “standing breech”. Or in Hogg’s language, the lug on the striker doesn’t actually have to first be pushed back by the cap in order to allow the locking cam to disengage, rather, the locking cam is slowed by the striker lug but ultimately just pushes it out of the way due to the overall movement of the bolt via normal blowback forces. Also, as gun author John Walter correctly points out, the 1895 US patent doesn’t mention anything about special ammunition attributes, something one would expect in a primer-actuated design.
So, unless Hogg had access to a real working example and observed its operation as being different than that described in the US patent, the myth of the primer actuated Schönberger-Laumann can be laid to rest.
What, then, are the actual specifics of the action used? The bolt is delayed by several specific mechanisms:
1) When the bolt is seated forward in the cocked/locked position, a connected, pivoting “locking bar” (J) sits down in a correspondingly shaped notch (h1). The straight angles of the bar and notch would by their own nature serve to help slow the rearward travel of the bolt since the locking bar would have to fight somewhat against an angled plane to disengage itself.
2) The force of the main action spring acts upon the bolt indirectly via a forked “breech bolt lever” (I) in contact with a projection (j4) located on the swinging locking bar rather than directly on the main bolt body itself. When the bolt is forward with the locking bar down the bolt lever under tension is positioned in such a way that it exerts a somewhat downward as well as forward force upon the locking bar. This compounding of angular forces acts as its own delay.
3) As has been noted, at the moment when the firing pin is at its forward-most firing position an integrated projection (g1) is then in contact with the top of the locking bar. This simply adds a further element of hesitation as the momentum of the just released firing pin and also the standing spring tension behind it must be overcome by the rising locking bar.
All of these conditions act in concert to delay the force of the charge. This arrangement calls to my mind roller-delayed and toggle-locked systems since they operate along somewhat similar force-redirecting principles.
Further weapon details:
The Schönberger-Laumann is reported to have fired a “7.8mmx19R” or “8x25mm” round from an internal magazine with a capacity of 5. Concerning the ballistics of the round in question, R. K. Wilson hypothesized that it propelled a 116 gr projectile to around 1,198 fps, figures remarkably similar to the 9mm Parabellum.
On the right side is a large reciprocating cocking lever that retracts the bolt partially out the rear of the frame, when done manually this also engages a holdopen that locks the bolt back. Just above the tang is the large rotating holdopen/safety whose left side is serrated. Pushing down on the left side releases the bolt and allows the pistol to fire, or with the bolt already closed another downward push engages the safety. After returning the bolt to battery the rear of the firing pin extends from the back of the bolt and can be used as a visual cocking indicator. On early Steyr models, and perhaps others, there is a .5” diameter checkered button, set in a raised escutcheon in front of the cocking lever, that acts as a magazine/clip release.
The pistol was either designed by or for two brothers of the last name Schönberger (who may have been associated with Steyr) and patented several times in different countries by Austrian Joseph Laumann in and around 1892. In his quest to design a reliable semiautomatic pistol, Laumann made a number of prototypes, most of which were produced for Austrian Army trials, and were never sold commercially. According to Ezell, the Schönberger-Laumann competed in the 1894 or 1895 Austrian pistol trials against the Salvator Dormus and two other unidentified early automatic pistols (one by Konrad von Kromar and another from Budapest, possibly an early Frommer prototype) and one revolver. A combination of unreliable charge powder and the usual prototype bugs meant that the Austrians did not end up adopting any of the automatics at that time.
- The top photo is of SN. 6 produced by Österreichischen Waffenfabriks-Gesellschaft (Steyr).
- The long center image is a compilation of all of the US patent’s drawings, a useful tool for anyone trying to make heads or tails of the patent text. I recommend having both the drawings and text open in different windows for quick reference.
- The bottom left image is a drawing from British patent 18,823 and appears to be far more useful than the US drawings.
- Bottom center looks to be a proof-of-concept one-off since it isn’t even fitted with sights and has a number of parts not seen on other models.
- Bottom right looks to be a later model with a different magazine release arrangement.