FN's 1950 Rotating-Bolt FAL Prototype Chambered in .30 Carbine

Ian McCollum of Forgotten Weapons got access to ARS Mechanica, the FN Browning Group's historical foundation, for a look at a rarely seen prototype from FN's early light automatic rifle program: a one-off FAL chambered in .30 Carbine, built and shelved between 1949 and 1951.

Key points

• Different locking system: instead of the FAL's familiar tilting bolt, this prototype uses a single-lug rotating bolt driven by a cam track in the carrier.
• Chambering and magazine: it runs .30 Carbine from a straight-in magazine resembling an M1 Carbine mag, rather than the FAL's standard rock-in design.
• Mixed-era features: it already shows later FAL traits like a left-side non-reciprocating charging handle and FAL-style rear sight, despite its early, experimental status.
• Unusual fire control group: the trigger mechanism is an M1/AR-style front-and-rear sear setup, not the standard FAL design, with a coil spring on the hammer axle.
• Never field tested: marked only "P004" with no proof marks, indicating it never left FN's facility or reached the Liège Proof House.

Quick take

McCollum describes the rifle as an offshoot experiment rather than part of the FAL's main line of development, used to try out locking systems and manufacturing methods. Only this one example was made, and he notes that no records of its performance or testing survive.

Watch the full video: Forgotten Weapons