FN FAL
Fusil Automatique Léger
FN Herstal1953–1988Early Cold War
Also known as L1A1 SLR, Right Arm of the Free World
Image credit
- Title
- File:Century Arms FN FAL.jpg
- Author
- Snark(attribution required)
- Licence
- CC BY-SA 3.0
- Source
- https://commons.wikimedia.org/wiki/File:Century_Arms_FN_FAL.jpg
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m9.525 g147.0 grverifiedsourcePublished as 147 gr; 1 gr = 0.06479891 g exactly.
- v853 m/s2,799 fpsverifiedMeasured with a 558.8 mm barrel, not this arm's 533 mm. Velocity outside the sourced range is not projected.
1 of 2 inputs link to their source.
How Muzzle velocity is calculated
nearest sourced barrel length — no extrapolation (SPEC.md §8.2)
Inputs
- v at 558.8 mm853 m/s2,799 fpsverifiedsourceBallistics table of the cited article.
Assumptions
- This figure belongs to a 558.8 mm barrel. It is shown because it is the closest measurement that exists, not because it applies here.
1 of 1 inputs link to their source.
How Loaded mass is calculated
m_loaded = m_empty + m_magazine + n · m_cartridge
Not calculated: m_magazine has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- One magazine, filled to the stated capacity. Spare magazines, optics, slings and lights are the owner’s, not the arm’s.
2 of 4 inputs link to their source.
How Free recoil is calculated
E_recoil = ½ · m_firearm · v_recoil²
Inputs
- m_firearm4.25 kg9.370 lbverifiedsource
- v_recoil1.912 m/s6.272 fpsestimated
Assumptions
- Propellant gas momentum is excluded: ARMAG does not record charge weights (SPEC.md §14). This is therefore a lower bound on the real free recoil, consistent between entries but smaller than a figure that includes the gas term.
- Free recoil: the arm is unrestrained. Stock design, muzzle devices, stance and shooter mass are not modelled, because none of them is a property of the arm.
1 of 2 inputs link to their source.
How Capacity is calculated
as published for the primary chambering
Inputs
- capacity20verifiedsourceDetachable box magazines of 20 and 30 rounds; a 50-round drum exists.
1 of 1 inputs link to their source.
Derived figures
Computed from the sourced values above. Open ƒ on any figure for the formula, its inputs, and the assumptions it makes.
How Momentum is calculated
p = m · v
Inputs
- m9.525 g147.0 grverifiedsourcePublished as 147 gr; 1 gr = 0.06479891 g exactly.
- v853 m/s2,799 fpsverifiedMeasured with a 558.8 mm barrel, not this arm's 533 mm. Velocity outside the sourced range is not projected.
1 of 2 inputs link to their source.
How Sectional density is calculated
SD = mass(gr) / (7000 · diameter(in)²)
Inputs
- mass9.525 g147.0 grverifiedsourcePublished as 147 gr; 1 gr = 0.06479891 g exactly.
- diameter7.85 mm0.3091 inestimatedsourceNo free dimensional standard publishes the NATO round under that name. Borrowed from the C.I.P. datasheet for the commercial .308 Winchester (G1), which shares the chamber; the two are not interchangeable at the pressure limit.
Assumptions
- Reported in the conventional lb/in² so it is directly comparable with published figures.
2 of 2 inputs link to their source.
How Power factor is calculated
PF = mass(gr) · velocity(fps) / 1000
Inputs
- mass9.525 g147.0 grverifiedsourcePublished as 147 gr; 1 gr = 0.06479891 g exactly.
- velocity853 m/s2,799 fpsverifiedMeasured with a 558.8 mm barrel, not this arm's 533 mm. Velocity outside the sourced range is not projected.
Assumptions
- A competition classification defined by the IPSC and USPSA rulebooks, stated in their units. It describes a scoring category, not an effect.
1 of 2 inputs link to their source.
How Magazine dump is calculated
t = (n − 1) / (rpm / 60)
Inputs
- n20verifiedsourceDetachable box magazines of 20 and 30 rounds; a 50-round drum exists.
- rpm675 rpmestimatedsourceThe article publishes 650–700 rounds/min. Recorded as the midpoint of that range.
Assumptions
- Cyclic rate held for the whole magazine, no stoppages, trigger held down. A theoretical figure for comparing mechanisms, not a measured one.
2 of 2 inputs link to their source.
How Sight error at 1 mm is calculated
θ = atan(misalignment / sight radius)
Not calculated: sight radius has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- Shows what a stated aiming error costs. The misalignment is the reader’s figure; the site does not claim how well anyone aims.
No input on this calculation carries a clickable source yet.
Specifications
Every row here is generated from the schema, so a figure recorded on this entry cannot be missing from the table — and the same rows, read the same way, are what the comparison shows.
Identity
- Type
- Rifle
- Action
- Self-loading
- Fire modes
- Semi-automatic
- Fully automatic
- Operating system
- Gas, short-stroke piston
- Designed in
- Belgium
- Introduced
- 1953
- Production
- 1953–1988
Dimensions and mass
Sights and rifling
- Sight radius
- not recorded
- Sight height over bore
- not recorded
- Rifling twist
- not recorded
- Twist direction
- not recorded
- Grooves
- not recorded
- Sight graduation
- 600 m656.2 ydsource
Ramped aperture rear sight, adjustable from 200 m in 100 m increments.
Chamberings
- 7.62×51mm NATOprimary20 rounds
Scale
A to-scale outline against family siblings. The dimensions are sourced; the shape is a representative outline for the type, and says so.
- FN FAL1,090 mm42.91 inheight not recorded
Representative outline — the dimensions are sourced, the shape is not. Overall length, and barrel length where recorded, are drawn from this entry's own figures; the profile is a generic one for the firearm type and says nothing about this arm's actual contours. FN FAL records no height, so its outline is drawn at the type's proportion — that height is part of the shape, not a measurement.
Detail
Dieudonné Saive designed it for the .280 British intermediate cartridge and was made to rebuild it around the 7.62×51mm after the United States refused to standardise on anything smaller. That decision is the central fact about this rifle: everything awkward about it — the recoil in automatic fire, the length, the 4.25 kg — follows from a cartridge its designer did not choose.
The mechanism is a short-stroke gas piston driving a breechblock that tilts downwards into a shoulder in the receiver floor, and it is unusually adjustable: a gas regulator with a graduated collar lets the rifle be tuned to ammunition or to a fouled action, which is a large part of why it worked in ninety countries.
Most of those countries issued it semi-automatic only, having reached the same conclusion the Americans did about a nine-and-a-half-pound rifle firing a full-power cartridge on automatic. The British L1A1 removed the capability entirely.
Its nickname came from the map: at the height of the Cold War it was the standard rifle of most of NATO and much of the non-aligned world, while the other side carried Kalashnikovs.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- FN FAL · Wikipedia · 1369793805 · read 2026-08-31 · CC BY-SA 4.0
Last verified 2026-08-31 · review status: agent-populated