Belgian Jacquemart Le Monobloc (One Piece) 6.35mm Semi-Auto Pistol C&R
SOLD FOR: $1,026.00
LSB#: LSB260412LW005
Make: Joseph Jacquemart, Herstal / Liège, Belgium
Model: Le Monobloc (The One Piece) “Pistolet Automatique Breveté”
Serial Number: 1283
Year of Manufacture: 1911-1914 / C&R
Caliber: 6.35mm Browning, .25 ACP
Action Type: Blowback-operated semi-automatic pocket pistol fed by a removable box magazine. The Le Monobloc is notable for its one-piece barrel/frame/receiver construction, the feature reflected in the “Monobloc” name.
Markings: The left side is marked “LE MONOBLOC” PISTOLET AUTOMATIQUE BREVETE”. There is a row of Belgian / Liège proof marks on the lower left front of the frame/barrel assembly. The right side is marked “1283” at the front of the frame/barrel unit, with additional small proof/inspection marks visible on the right-side oval panel. The rear of the pistol is also numbered “1283”. The trigger is marked “83”. The safety area is marked “S”. The grip panels have molded intertwined “JJ” monograms.
Barrel Length: Approximately 2 1/8 inches / 52–53 mm
Sights / Optics: The front sight is a blade fixed to the top of the frame at the front. There is no rear sight. The rear sighting reference is a rudimentary fixed rear notch/receiver sighting groove.
Stock Configuration & Condition: The grips are black hard rubber / composition panels with molded checkering, raised border decoration, and circular intertwined “JJ” monograms. The panels show age wear, handling marks, softened checkering, scuffs, and small edge wear. The grip screws show slot wear. There are no chips or cracks. Overall, the grips rate in Very Good condition.
Type of Finish: Blued steel
Finish Originality: Most of the finish appears original while some areas have been touched up with cold blue.
Bore Condition: The bore is somewhat dark with well defined rifling. There is light erosion throughout. In this writer’s opinion the bore rates 5/10.
Overall Condition: This pistol retains about 35% of its current finish. The metal retains traces of old blue in protected and recessed areas, with the majority of the exposed surfaces worn to gray and brown patina. There is scattered oxidation, pinprick pitting, handling wear, scratches, nicks, and edge thinning throughout. The most notable finish loss and surface wear appear around the muzzle, front frame/barrel unit, top surfaces, slide/receiver flats, and high edges. The serrations remain visible. The serial number and principal markings remain legible. The screws show use and slot wear. The grips remain present and displayable, with wear consistent with the rest of the pistol. Overall, this pistol rates in Fair – Good condition.
Mechanics: The action functions correctly, as does the safety. We did not fire this pistol. As with all used firearms, a thorough cleaning may be necessary to meet your maintenance requirements.
Box, Paperwork & Accessories: None.
Our Assessment: This is a scarce Belgian Jacquemart Le Monobloc semi-automatic pocket pistol chambered for 6.35mm Browning / .25 ACP. The design is historically interesting because the barrel and frame/receiver assembly were made as a single “monobloc” unit, an unusual construction method among early European vest-pocket pistols. The pistol is marked with the distinctive “LE MONOBLOC” PISTOLET AUTOMATIQUE BREVETE legend and retains the desirable JJ monogram grips. While this example shows heavy finish wear, patina, scattered pitting, and substantial honest age, it remains a recognizable and collectible early Belgian automatic with visible matching serial markings on the frame/barrel unit and rear. This is a good candidate for a collector of obscure European pocket pistols, Belgian Liège automatics, or pre-WWI self-loading handgun designs. Please see our photos and good luck on your bid! – L.S.