Sterling submachine gun
Sterling Armaments Company1953–1988Early Cold War
Also known as L2A3, Patchett machine carbine
Image credit
- Title
- File:Submachine Gun, 9mm, L2A3, Sterling, British, S-N UF57A5347 (NHHC 2002-11-2) (Right side, stock unfolded).jpg
- Author
- Unidentified US Naval History and Heritage Command photographer
- Licence
- Public domain
- Source
- https://commons.wikimedia.org/wiki/File:Submachine_Gun,_9mm,_L2A3,_Sterling,_British,_S-N_UF57A5347_(NHHC_2002-11-2)_(Right_side,_stock_unfolded).jpg
_(Right_side,_stock_unfolded).jpg){kind=link}
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- v359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 196 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
Inputs
- v at 101.6 mm359.7 m/s1,180 fpsverifiedsource1180 fps as published.
Assumptions
- This figure belongs to a 101.6 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_firearm2.7 kg5.952 lbverifiedsource
- v_recoil0.9928 m/s3.257 fpsestimated
Assumptions
- Propellant gas momentum is excluded: ARMAG does not record charge weights. 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
- capacity34verifiedsourceA curved 34-round magazine; Sten and Lanchester magazines of 32 and 50 rounds also fit.
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
- m7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- v359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 196 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
- mass7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- diameter9.03 mm0.3555 inverifiedsourceCartridge maximum, dimension G1.
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
- mass7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- velocity359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 196 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
- n34verifiedsourceA curved 34-round magazine; Sten and Lanchester magazines of 32 and 50 rounds also fit.
- rpm550 rpmverifiedsource
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
- Submachine gun
- Action
- Self-loading
- Fire modes
- Semi-automatic
- Fully automatic
- Operating system
- Blowback, simple
- Designed in
- United Kingdom
- Produced in
- 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
- not recorded
Chamberings
- 9x19mm Parabellumprimary34 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.
- Sterling submachine gun686 mm27.01 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. Sterling submachine gun records no height, so its outline is drawn at the type's proportion. That height is part of the shape, not a measurement.
Detail
George Patchett designed it in 1944 to replace the Sten, and the single change that matters is the magazine. The Sten fed from the left through a straight magazine with a double-column-to-single-column transition that jammed constantly; the Sterling feeds from the left through a curved magazine with rollers instead of a plain follower, and it does not. That is most of the reason the British Army carried this weapon for thirty-five years.
The rest is conventional open-bolt blowback executed carefully: a tubular receiver with helical ribs machined inside it that scrape fouling away from the bolt, a folding stock that actually locks, and a cyclic rate of about 550 rounds a minute. That is slow, which is what makes it controllable.
The suppressed L34A1 version is the one that turns up in films, with a barrel drilled with seventy-two holes inside an integral suppressor.
Its maker has no founding year on this site, and that is not an oversight: no free source publishes one for Sterling Armaments, and the maker page records the gap rather than a guess.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- Sterling submachine gun · Wikipedia · 1366339843 · read 2026-08-31 · CC BY-SA 4.0
Last verified 2026-08-31 · review status: agent-populated