Steyr-Hahn's are strong pistols. The original 9mm's were factory converted from 9mm Steyr to 9mm Para by manufacturing new barrels in the latter caliber and done so by either Mauser or Steyr. Experts seem to disagree on exactly who did the conversion barrels.
I don't think the Germans would have authorized that modification if they thought it was inherently dangerous. However, I don't know anything about these newer aftermarket barrels in terms of steel quality, machining tolerances, and proofing.
Per your reference "
most reloaders say to use 9x19 load data in 9x23 anyways", the rationale is that using 9mm Para loads in the 4mm longer 9mm Steyr case drops the pressure considerably by virtue of a lower loading density, and that a maximum 9mm Para load in a 9mm Steyr case is considered safe for use in unconverted 9mm Steyr S-H pistols. I think personally that this is correct, based on personal experience. YMMV. I still prefer to reduce my 9mm Para loads though out of an abundance of caution philosophy.
I'm using 4.0 grains of WW231 behind a 115 grain plated RN bullet, a 20% reduced 9mm Para load with 115 grain plated bullets that allows the action to function and provide accurate-enough groups in my Nazi conversion S-H with much lower pressures. I also load for 9mm Steyr and what little reloading data that is out there suggest (to me at least) that 9mm Steyr operates at a max pressure of 16,000 psi, half what 9mm Para runs. However, again I say that the Steyr-Hahn is a very strong design.
I also think it is good to note that the original 9mm Steyr cartridge used 115 grain bullets, one of the few exceptions to 123/124 grain bullets found on most other Nazi 9mm service pistols.
Lots of guys shoot their converted S-H's with factory 9mm Para ammo and I just don't hear of problems when using the original 1930's converted barrels. Everyone needs to make their own mind up as to what ammo, if any is safe. People are gonna have conflicting opinions on this topic.
20+ years ago there was a guy named Randy Rick that was a student of the Steyr-Hahn with its many variants. He wrote a very good article about them. What little I know about them seems to agree with his assessments. He was in the middle of writing a book about S-H pistols at that time but I don't know if he ever finished it or not.
Here's the article below. It's an internet article but well-done and informative, IMHO. Microsoft Word files don't do well on Gunboards so I just pasted the 5-page doc. -Bob
The Austrian Steyr-Hahn Pistol M1911/M1912 By Randy Rick
The Steyr-Hahn (hahn is German for hammer) pistol was first produced in 1911 with a fixed blade front sight, the model M11. It is an 8 shot top loader that is stripper fed, shooting the 9mm Steyr cartridge. The model M12 with dovetailed front sight is otherwise identical. The M12 was evaluated for military use, but was not adapted by the Austrian Army until the First World War began. The gun was produced until 1919 although it is believed that many were assembled from parts for several years thereafter. The Romanian police used the Steyr-Hahn and that version bears a Romanian Crest. The Chilean Army adopted the M11 and that model bears a crest also. It should be noted that serial numbers for the Romanian contract guns are directly continued into the guns produced for the Austrian Army, when the contract for Romania was discontinued. Guns with both Romanian contract parts and Austrian acceptance proofs are common for this transition period. About 300,000 were made in all. A few Steyr-Hahns Model M16 in full auto with extended magazines were used in WWI and by early Austrian Nazis. The Czechs were known to have converted some military issue Steyr-Hahns to full auto with a similar mechanism as the factory produced weapons but without the extended magazine. A wooden shoulder stock/holster with a cup that accepts an unaltered Steyr-Hahn's frame about the grip is occasionally seen.
The serial number typically appears in 3 places, the left frame above the trigger, and immediately above that on the left center slide. The serial number will also be on the barrel, sometimes without the trailing alphabetic suffix. Rarely the serial number will be on the grip's butt.
The grips are typically a brown stained wood with a raised crosshatch pattern. They are slid into cuts in the frame and secured with a single screw through the frame at the grip butt.
All parts show small proof stamps consisting of the initial of the person who proofed the weapon.
Design:
The final design was by Chief Engineer Konrad Murgthaler. It was based on earlier design work by Karl Krnka, Georg Roth, and Ferdinand Mannlicher. The Steyr-Hahn is a large frame semi-auto, single action pistol. The slide is retained on the frame by a keeper similar to that on the 1905 Colt. The action is that of a rotating barrel which is kept locked by the action of the bullet passing thru the bore. When the bullet has left the bore, the barrel is free to rotate and unlock the slide, which recoils to the rear. It is otherwise similar to other semiauto pistols with a recoil spring under the barrel which is retained by the keeper pin. It has an external hammer with a small spur. There is a safety on the frame, below the hammer, which locks into a notch in the slide. There is also a notch halfway along the slide which will hold the slide back with the safety. The slide will be held back after the last round is fired by the back of the cartridge follower from the magazine well. The trigger pull is transmitted via a transfer bar under the slide which pulls forward the sear, and releases the hammer.
To load, with the slide back, raise the safety into the notch in the slide to lock the slide back. Insert a stripper clip into the clip glide in the slide's ejection port, and strip the cartridges into the magazine well. Cartridges can also be single loaded in this manner. To unload the magazine well, lock the slide to the rear with the safety; then push down on the magazine release above the left grip.
Holster variations are considerable. A holster with shoulder strap and stripper clip pouch was common for Austrian guns.
Variations:
1911 Commercial Model. May have adjustable rear sight. Will have the words 'OESTERR.WAFFENFABRIK STEYR M.1911 9m/m' on left slide. There were not large quantities sold commercially. This model may have a larger reinforcement area around the locking wedge (near the muzzle); which Zhug refers to as the model 1910. May have NPv commercial proofs.
- Marine-Pistole M12. Will have tangent rear sight and a higher front sight. Some with extended barrels. rare.
- Adjustable Rear Sight 1912/M1911. Fixed front sight. Has standard rear sight, but with the v-notch opened up. A dovetail is cut horizontally across the back of the rear sight base. A small plate with a v-notch rear sight rides in the dovetail. Left side of slide has the stamps 'STEYR 1912 MOD.1911'.
- Fixed Rear Sight 1912/M1911. Fixed front sight or dovetailed front sight (high serial numbers). Left side of slide has the stamps 'STEYR 1912 MOD.1911'.
- Chilean Model. Will have crest on left front side that is of a huemul (deer) and a condor on either side of a shield with a star in the center. In the center of the left slide it will state STEYR 1912, and to the rear left slide MOD.1911. On the left rear slide it will state 'EJERCITO DE CHILE'. There will typically be a "crossed miners' hammers" proof on the top of the slide. Fixed front sight. There were 5,000 Chilean M1911's manufactured. The serial numbers are unusual in that they run nnn, 1nnnA, 2nnnB, 3nnnC, and 4nnnD.
- Romanian Model. On the left front of slide will have a crown over the inscription "Md.1912". At the rear of the left slide it will state STEYR (1912, 1913, or 1914). There will be a Romanian Phoenix (bird) over the trigger on the right frame. It is common to find Romanian guns that have been altered with two cuts in the rear of the grip and a notch cut in the rear grip strap to accept a shoulder stock. Dovetailed front sight. A large number of the Romanian Steyr-Hahn pistols were captured by the Austrians during WWI, hence one will see them with the later "08" conversion to 9mm Luger and/or with post WWI Czech proofs.
- Austrian Army issue M12. Will have STEYR19xx (date) on the left rear of the slide. On the right frame above trigger it will have "Wn eagle xx"; the digits xx are the year of military acceptance, normally 1914 thru 1919. Dovetailed front sight.
- Nazi proofed. Guns were taken from captured arsenals and sent to Mauser to be refurbished and to be fitted with 9mm parabellum barrels. The barrels were serial numbered to the gun and have a nazi eagle. The guns were typically proofed with '08' on the left slide towards the front. Eagle/N and Delta-dot on left frame over trigger. And eagle/L on right frame over trigger. Both Austrian army and Romanian guns are found that have been re-worked.
- Bavarian Contract. The Army of Bavaria procured 10,000 Steyr-Hahns in 1916, and 6,000 in 1918. These are identical with the Austrian Army variation. They can be identified by the fact that the serial number does not have an alphabetic character suffix and they are dated either 1916 or 1918. These guns may be seen with Prussian military proofs either on the front of the trigger guard or left side of frame behind the trigger.
- Model 1916 Machine Pistol. There are conflicting stories about how many of these were produced. I believe that only a few hundred were made and that they came out of the guns otherwise serial numbered for the Bavarian contract.
- Steyr sent several guns as examples or trial guns to many countries who might do business with them. There was a small contract with Turkey. There were presentation sets made up for gifts to officials or businessmen. There were spare parts from all the production runs which later were assembled into weapons.
Other Common Proofs:
The Austrian commercial proof NPv (Nitro Proof Vienna) is frequently seen on guns that were sold as surplus, or for other reasons. Steyr-Hahns which were issued to the Austrian Army in between the wars may carry a proof 'HV eagle XX' (xx=year). Police issued guns may carry the proof LGK-state or SW on the lanyard loop. Guns that were in Czechslovakia after the breakup of the Austro-Hungarian Empire are frequently seen with Czech proofs (CSR, Czech standing lion, etc). (LKG stands for Landes Gendarmerie Kommando, a Nazi state police agency).
Ammunition:
The 9mm Steyr is 9x23mm typically with a 115gr nickel jacket. Midway used to make boxer primed Steyr-Hahn ammo. Fiocci is currently importing it, but it is not common. A small quantity of modern manufacture Hirtenberg boxer primed ammunition was recently available. Pre-WWII surplus ammo is relatively common, and should not be too expensive. GECO, RWS, and DWM ammunition from the 1930's can be found in boxes of 50 cartridges, or boxes of 16, on 2-8round stripper clips. This 1930's ammo is non-corrosive, berdan, and shoots well. Look for the word 'Sinoxide' on the ammo box that means non-corrosive. Surplus ammo from FN is also available, but it is not of the quality of the other ammo, and is corrosive. Pre-1930's ammo is very rare, and should be considered 'collectors ammo'. Examples of WWI ammo from Hirtenberg, Roth, Sellier & Belliot and others can be found.
Reloading:
Steyr 9mm cartridges can be reloaded with 38super (or .38/.357) dies using a 9mm shell plate. A moderate 9mm para powder load for 115gr FMJs should be acceptable. Grafs has new manuf boxer cases of Hornady headstamp. One can also use 9x23Win cases loaded to 9mm Steyr levels.
Production Information for the Steyr-Hahn
The small letter proofs found on the Steyr-Hahn are the last initial of the person inspecting the part. The most common inspection stamp is the letter "K", the proof of Meister Josef Kogler.
Information Being Compiled:
I am writing a book about the Steyr-Hahn. I would appreciate receiving specific information on as many of these pistols as possible. Things I am interested in are serial numbers, all proofs & their locations, unit markings, unusual sights or other features. Also, information on holsters or original photographs are much appreciated.
Production Information for the Steyr-Hahn
These pistols used the alphabetic letters sequentially, a,b,...x,y,z as a serial number suffix. That accounts for 260,000 pistols. There were a few exceptions or special runs of pistols. If WWI had lasted a couple more years I'm not sure what would have been used as a suffix after z?
Serial Number year
(blank),*, a,b,c 1913
4500c 1914
6000d 1914 (end of Romanian contract)
1405g 1915
1482g 1914 (hmm?)
6322k 16 on slide / 15 proof date
9155q & 3890r 17 on slide / 16 proof date
(It appears the factory changed over their stamp on the slide before the Army inspectors got new proof stamps)
8768v 1917
6423w 1918
3124y 18 on slide / 19 proof date
9550z 1919 highest 'z' seen
Production Number Estimates by Year:
Chilean M1911 contract(1912) 5000
Austrian/Romanian thru 1913
(inc commercial) 50000
Romanian 1914 12000
Austrian 1914 26000
Austrian 1915 44000
Austrian 1916 65000
Bavarian 1916 10000
Austrian 1917 50000
Austrian 1918 23000
Bavarian 1918 6000
Austrian 1919 17000
Misc Parts Guns 5000
Total Production 313,000 guns
rec.gun article on shooting the Steyr-Hahn with Bergman ammo