Patchett Machine Carbine Mk I

Sterling Engineering Company · Submachine Gun · Prototype · 1944

Also known as: Patchett Machine Carbine, Patchett 9mm Mk I, Patchett Mk 1

Overview

The Patchett Machine Carbine Mk I was a British wartime prototype submachine gun designed by George Patchett of the Sterling Engineering Company. Built around a Sten-derived receiver tube with a Lanchester-style magazine well and ventilated shroud, it introduced the helical bolt ribs that would become a Patchett trademark, clearing fouling from the action. The prototype was a precision-machined trials weapon submitted to the British Ordnance Board in 1944; it won the competition but, with the postwar drawdown, was not adopted until it had been refined into the production Sterling submachine gun in the 1950s.

Specifications

Weight (empty)3400 g (119.9 oz)
Weight (loaded)3860 g (136.2 oz)
Barrel Length198 mm (7.80")
Action TypeBlowback
Firing MechanismHammer Fired
Trigger TypeSingle Stage
Magazine Capacity32 rounds
Magazine TypeDetachable Box
Effective Range100 m (109 yd)
Maximum Range200 m (219 yd)
Rate of Fire550 rpm
Barrel RiflingRight Hand
Frame MaterialSteel
Barrel MaterialSteel
Stock MaterialSteel
FinishBlued

Calibers

Features

Service history

Operators

Conflicts

Production

Estimated total produced: 110 · Production years: 1943-1945

Trials weapon; an Imperial War Museum specimen is stamped 'PATCHETT MACHINE CARBINE MK 1 No 078'. Refined into the Sterling SMG, adopted by Britain in the 1950s.

Origin

Country of origin: United Kingdom

Designer: George William Patchett

Discontinued: 1945

Notes

Distinct from the production Sterling/L2A3: this is the WWII experimental machine carbine (~110 made, straight 32-round Sten-type magazine on early examples), not the mass-produced postwar weapon with its curved 34-round magazine. Sources vary on exact weight (a quoted 8.5 lb includes bayonet, sling and loaded magazine) and on whether ~20 or ~120 trials guns were ordered.

Background

Legend holds that a handful of prototype Patchetts were jump-tested by paratroopers at Arnhem in 1944; three serial-numbered trials guns vanish from British paperwork around that date, fuelling the story, though it has never been confirmed.