Precursor to the High Power: FN's 1923 Prototype Model Stocked Pistol

Historical Background and Development

After World War I, the French Army considered its handguns obsolete and sought a modern semi-automatic pistol. Its wartime inventory included a varied mix of handguns, including inexpensive Spanish-made .32-caliber pistols. The initial requirement called for a 9 mm pistol.

FN joined the competition. Dieudonné Saive, John Moses Browning’s protégé at FN in Belgium, began by adapting the FN Model 1903 and developing a high-capacity magazine. Browning then designed a new 9 mm locked-breech pistol around that concept. The version presented for French trials in 1922 had an internal hammer and a double-stack, single-feed magazine.

The French wanted FN’s submission to be lighter and to have an external hammer. Browning revised the design, producing the 1923-pattern pistol featured in the video.

French trials continued for years, with repeated testing and requested changes. By about 1928–29, FN split development into two tracks: one continued for the French trials, while the other became the Grand Puissance, or GP35—the pistol later known as the Browning Hi-Power.

France ultimately did not buy the FN pistol. Belgium showed interest in the Hi-Power around 1931 and adopted it as the GP35 after further development.

The 1923 Prototype and Its Distinctive Features

The featured pistol is an early Grand Rendement (“high-efficiency”) model, a predecessor to the Hi-Power. It has an extended barrel and an experimental detachable shoulder stock.

Its tangent sight is graduated to 500 metres. The French were interested in pairing a stocked pistol with a long-range sight so it could serve, when needed, as a small carbine. FN tried several stock designs; the unusual folding steel brace shown in the video was one of them.

The stock initially looks awkward, but the presenter finds it reasonably stable and usable. Its folding mechanism unfolds in stages and locks when fully extended. Bending the stock’s upper section releases it for folding.

The pistol has a 15-round magazine resembling a recognizable Hi-Power magazine. Later French-requested weight reductions led to a 13-round magazine in the eventual Belgian pistol. The presenter explains that the Hi-Power’s original 13-round capacity could later be increased to 15 with replacement or modified magazines.

Compared with the later Hi-Power, this prototype lacks a slide-stop pin and uses a removable breech block for disassembly. Its sight is mounted on the barrel shroud, which forms part of the slide, while the barrel sits inside it.

The pistol has an exposed hammer and a button-operated safety: raising the button prevents the hammer from falling. It also has a magazine disconnect, which prevents the trigger mechanism from operating without a magazine.

Operation and Mechanical Design

The pistol uses a tilting-barrel, locked-breech system. As the slide moves back, a cam track lowers the barrel, disengaging its locking lugs from recesses in the slide.

The prototype’s barrel cam is an integral feature inside the frame, rather than the separate pin used in the later Hi-Power arrangement.

Its fire-control mechanism already includes several features that carried forward into the Hi-Power:

• Pulling the trigger lifts a plunger behind it.
• The plunger moves a rocker beam, which presses down on the sear and releases the hammer.
• The beam also helps prevent firing when the slide is not fully in battery.
• The magazine positions the beam so the trigger mechanism can engage it; without a magazine, the beam is misaligned.
• A half-cock notch provides an additional safety position.

A fixed ejector also limits how far the magazine can be inserted.

The spring-loaded firing pin is designed not to protrude merely from being pushed flush with the rear of the slide; it requires the impact of the hammer to move forward sufficiently. The presenter notes that such safety features were not yet commonplace in the early 1920s.

Field-Stripping Sequence

1. Fold the shoulder stock out of the way by releasing its latch and collapsing the hinged sections.
2. Pull the slide fully back.
3. Hold it in position using the trigger guard.
4. Rotate the breech block 90 degrees clockwise.
5. Let the slide move forward so the breech block can be removed.
6. Remove the slide from the front of the pistol.
7. With the slide removed, inspect the barrel, locking lugs, cam track, and recoil spring.

The prototype already resembles the later Hi-Power in its general layout and several core mechanisms, although its sights, stock, breech-block arrangement, and some internal details changed during subsequent development.

Speakers and Sources Featured

• Ian McCollum — presenter and narrator.
• Ars Mechanica — the FN/Browning historical foundation whose collection includes the pistol and which provided access for filming.
• FN Browning Group — the organization associated with the collection and the company history discussed in the video.
• Historical figures discussed but not speaking in the video: John Moses Browning and Dieudonné Saive.