As most of you know, the US 9mm Pistol M9 uses a pivoting block design, originally developed and patented in 1950 by engineer Tullio Marengoni of Beretta of Gardone, Val Trompia, Italy. But he drew, of course, on the 1936 design by engineers at Carl Walther Waffefabrik, then in Zella-Mehlis in the state of Thuringia, Germany, that would become the P-38 locking system. However, Walther’s designers, Fritz Walther himself and Fritz Barthelmnes, drew in turn upon earlier work by the Mauser-Werke’s Josef Nickl and Nickl’s own mentors, the three Feederle brothers. Thus does one feature of one famous firearm bear the stamp of not just one, but seven brilliant designers, each one of whom has passed on and each of whom is better known for other firearms!
There are actually more designers involved than that, because the Beretta M92/M9 has undergone quite a bit of engineering work in recent years, after production engineering “improvements” over the original M1951 materials and methods turned out to reliability engineering disasters; but the original M92/M9 locking block was very little altered from its M1951 forebear.
To tell the whole story, we must go back to the beginning of automatic pistols and the Feederle brothers, Friedrich, Fidel, and Josef, the developers of the Mauser 1896 pistol, the famous “broomhandle,” the first commercially successful self-loading automatic pistol. By 1907 they were working on a new design that involved a large pivoting block as shown in German Imperial Parent (D.R.P.) Nº. 209513. (The patent is in Paul Mauser’s name, as was normal in the Mauser-werke, but it was the Feederles’ work). The locking block of the experimental 1907 Mauser is large and located behind the breech face in the rear of a slide, but the way it pivots to lock the slide to the barrel during the short recoil is the first invention on the way to the M9’s locking system. But the Feederle brothers are certainly best-known for the C96, which used a different locking method entirely.
A Feederle protégé brought the next innovation into the design when Bavarian engineer Josef Nickl began experimenting with breech locking. Nickl’s goal was to update the Mauser 1910/1914 pocket pistol to a more powerful cartridge like the 9mm Parabellum, and he tried many different kinds of locked-breech mechanism to make this work. At one time or another, he experimented with flap-locking ike a Degtyaryev machine gun, a rotating barrel like the Mexican Obregon, and the mechanism in which we’re interested in — a pivoting locking block that moves much like a Beretta locking block, but is mounted below the barrel. This patent — credited, as usual, to Paul Mauser — was DRP Nº. 250493 of February 5, 1911.
A prototype, serial number 4, survives and has passed through several top-flight collections, including Dr. Geoffrey Sturgess’s. The following Nickl prototype pistol will be in the RIA April auction. It’s in .45 caliber (one of several such Mauser-werke prototypes) and may be flap or pivoting-block locked (it’s not clear). It is marked with the serial number “2”.
The following is 9mm pistol, serial # 129, showing the “chipmunk cheeks” of the Nickl pistol using Degtyaryev locking-flaps. It too is in the RIA April auction.
Nickl, though, is not famous at all for his locking block, which is a footnote to Mauser’s efforts at best. He is best known today as the father of the first “native” Czechoslovak firearm, the Vzor (Model) 24 pistol, a barely-modified, badge-engineered version of one of his Mauser prototypes. Nickl offered it to the Czechoslovaks while installing a Mauser-built production line for rifles at the Zbrojovka Brno plant.
When the Walther firm developed a 9mm pistol bringing their double-action, single-action / safety-decocker concept to the service pistol, their design had three new patented features: the dual recoil springs, the hammer design, and — germane to our subject here — the locking block. While Fritz Walther, son of Carl whose name was on the letterhead, was involved in the design, the principal design seems to have been that of engineer Fritz Barthelmnes, then a Walther employee. According to Bruce’s excellent book, Walther’s name alone appears on the relevant German patent, DRP 721702, applied for 21 October 1936 and issued 15 June 1942, but Barthelmnes is actually also credited on the patent and on derivative foreign patents.
The key feature of the Walther block, missing from earlier versions, is the unlocking or disengaging pin that ensures positive unlocking of the block (#12 in the illustration above).
Barthelmnes is known, of course, for the P.38, but he’s arguably better known for his own postwar FB-Record blank and air pistols.
Which brings us to Italy and Tullio Marengoni. At a glance, Marengoni’s 1950 patent (Italian Patent Nº 467871) appears almost identical to the Walther patent. In fact, we were unable to get our hands on the Italian patent and see just what Marengoni is claiming that Walther and Barthelmnes didn’t in their 1936 patent — but it’s interesting that Marengoni does not cite the two Fritzes’ patent at all, according to the patent citation records at the German patent office. (This may be caused by the German database not seeing foreign patents). If we can get a hand on Marengoni’s patent, we’ll see if we can determine where his design differs from Walther’s (a diagram in Bruce’s book does show that one of the claims was the Beretta disconnector, quite different from a P.38’s).
So next time you check an M9 out of the arms room, take a good look at that block! You’re handling the best efforts of many of the world’s greatest firearms inventors, all the way back to the first auto pistols in the 19th Century.
Bruce, Gordon. The Evolution of Military Automatic Pistols: Self-Loading Pistol Designs of Two World Wars and the Men who Invented Them. Woonsocket, RI: Mowbray Publishing, 2012.
German Patent Information System Network (DEPATISNET). Various historical patent documents. Searched at and Retrieved from https://depatisnet.dpma.de/