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

An L2A3 from the US Naval History and Heritage Command collection, stock folded. The holes along the barrel jacket are cooling ports; the magazine, which is fitted on the left, is absent here.

Muzzle energy

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.

482.1 J355.6 ft·lbf

Muzzle velocity

How Muzzle velocity is calculated

nearest sourced barrel length — no extrapolation (SPEC.md §8.2)

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.

359.7 m/s1,180 fps

Loaded mass

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.

not recordednot recorded

Free recoil

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 (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.

1.331 J0.9814 ft·lbfestimated

Capacity

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.

Momentum

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.

2.680 kg·m/s

Sectional density

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.

0.1300 lb/in²

Power factor

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.

135.7 gr·fps/1000

Magazine dump

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.

3.600 s

Sight error at 1 mm

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.

not recordednot recorded

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
Feed: Detachable box magazine
Roles: Personal defence
Service rifle
Designed in: United Kingdom
Produced in: United Kingdom
Canada
India
Introduced: 1953
Production: 1953–1988

Dimensions and mass

Mass, empty: 2.7 kg5.952 lbsource
Magazine, empty: not recorded
Length: 686 mm27.01 insource
Stock extended.
Length, folded: 481 mm18.94 insource
Stock folded.
Width: not recorded
Height: not recorded
Barrel length: 196 mm7.717 insource

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

Operation

Cyclic rate: 550 rpmsource
Trigger pull: not recorded
Effective range: 200 m218.7 ydsource
Units produced: 400,000source
The cited article gives "400,000+", so this is a floor rather than a count.
Launch price: 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.

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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 — 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