The DeLisle Silenced Commando Carbine

Whilst neither a training weapon nor a small-bore conversion, this arm is nonetheless a noteworthy conversion of a Short Magazine Lee-Enfield Rifle (S.M.L.E.)

It is also unusual in that the conversion entailed an increase in calibre rather than a reduction, albeit from the .303-inch centre-fire rifle round to the .45- calibre Colt Automatic pistol round.

The carbine design was conceived at Dagenham (the Essex home of the Ford Motor Company) by William G. de Lisle and Sir Malcolm Campbell (famous World Land and Water Speed record contender and holder, and father of Sir Donald Campbell) specifically for covert operations, such as those of Commandos initiated by Sir Winston Churchill, and others organised by the British Special Operations Executive (SOE). Trials of this carbine were undertaken in 1943, and de Lisle had successfully applied for a patent, number 579,168 issued on 8th. May 1943, for the specific design of the silencer, although the principle of a baffled silencing system had been used by Hiram Maxim many years earlier.

The assembly of the weapon was a fastidious task involving the careful choice of tolerances between parts, and small but critical modifications to render the action as quiet as possible in operation. Even the underside of the bolt-handle had a dovetailed recess milled to accommodate a rubber, leather or plasticised pad which prevented the customary loud 'clunk' given by the striking of the handle against the butt-socket when the bolt was closed quickly.

Being largely deLisle's project, the carbine was prototyped by his team at Dagenham and subsequently manufactured, by Sterling Armament, in numbers probably rather less than the originally contracted figure of five hundred; it has been suggested that as few as 120 were forthcoming, although an example in the small-arms collection of the Shrivenham-based U.K. Defence Academy is serial numbered 209. The early prototype models used a steel moderator casing, which was given a phosphated finish. Sterling production utilized a blacked alloy casing.

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Image of cancellation letter by courtesy of the Pattern Room Library now resident at the Royal Armouries Museum, Leeds.

Around mid 1943, the carbine was compared with a silenced version of that famous and reliable sub-machine gun - the Sten. The de Lisle product was, however, initially deemed not to be as quiet as the Sten equivalent although, by early 1944, a further trial of two submitted carbines gave rise to an appraisal which stated that "the guns appeared to be less noisy than the Sten [Mk.II (S)] and gave a smaller group [5 rounds], the best group being 1¾" x 1" at 20 yards, as against the best Sten group of 4" x 2½" at 20 yards." Large batches of ammunition were fired through both the Sten and the de Lisle, with one run of 5,000 rounds proving that, whilst coking of the baffles with powder residue caused silencer disassembly difficulty, and cleaning was required after a very few hundred rounds had been put through the weapon, the system of solid offset baffling through a comparatively large volume gas containment tube, where the bullet suffered no physical contact with any part of the suppression components, worked considerably better than some had expected.

Eventually, the design evolved to be almost as quiet as the equivalently purposed "Welrod" silenced pistol of the same calibre, although that very specialist side-arm held only very short range capability and utilised rubber and textile baffles through which the bullet was fired; these required replacement after the firing of but a few rounds. In 1957 the "de Lisle" was reappraised with a view to " its possible use in Malaya". It was noted then that the carbine "is designed fundamentally as a silent carbine, and is NOT a carbine fitted with a silencer". The report went on to say that the 'de Lisle' was then considered an ideal weapon for silently dealing with any sentries discovered during jungle patrolling operations. There are certainly reports that the weapon was issued in this theatre, as has been the case in Northern Ireland and indeed Korea. There have even been claims for the carbines believed usage in more recent times, although these are unsubstantiated.

Image courtesy of The Infantry and Small Arms School Corps (SAS C) Weapons Collection

The cutaway moderator illustrates the baffle arrangement. The baffles are supported by two rods horizontally positioned either side of the bore-line (the right hand rod is here visible). The barrel is of the order of 9 inches in length, including a bell-mouthed nozzle at the muzzle, and is accommodated entirely within the perforated section of the moderator tube immediately in front of the action body. The rear-sight fitted is that of the Lanchester submachine gun. The magazine shown could be replaced with an extended version with a capacity of reportedly twenty rounds, although it was likely to have been no more than double the eight rounds of a standard Colt 1911 pistol magazine.

The conversion consisted of removal of the .303 calibre rifle barrel and magazine, followed by replacement with a modified .45 calibre Thompson sub-machine gun barrel, bell-mouthed as mentioned, and modification of the magazine-way to accommodate a .45 auto pistol magazine from the Colt 1911 model. The final addition of one of the most efficient moderating systems ever devised, resulted in a short and silent arm considered to be effective beyond expectation. The manner in which, on many of the carbines, the bolt was shortened and the breech-end of the barrel brought rearwards into the original .303 receiver of the S.M.L.E. No.1 being converted, is reminiscent of the configuration of the post-war training and target Enfield Rifle No.8. in .22RF.

Original testing included trials with a down-loaded .303 cartridge, possibly loaded with pistol type bullet-heads, and the 9mm Parabellum round as well as the finally selected Colt .45 Auto cartridge, which was proven to have "the most suitable ballistics" and "the best residual striking energy". Several prototype carbines were constructed with phosphated steel silencer bodies, prior to the adoption of the weight-saving aluminium version finally put into production with Sterling Armament. An example is shown below, illustrated by courtesy of the Trustees of the Pattern Room Collection. This prototype was not yet fitted with the rubber bolt-closing quitening-pad eventually added into the milled dovetail in the underside of the bolt-handle. The aforementioned pad prevented the notably audible metallic clonk, familiar to the firer of any Lee-Enfield, made as the bolt-handle connected with the receiver body socket as the bolt was closed.

The quite basic fabricated sights fitted to this prototype were probably "in-house" manufactured, rather than the Lanchester sub-machine gun sights which were used on the production de Lisle silenced carbine. The rear-sight is almost akin to those seen on cheap air and small-bore sporting rifles of the day.

Apart from it being a conversion of the S.M.L.E., a further justification for the inclusion of this full-bore service weapon within our training and miniature-calibre remit, is that de Lisle did perceive the need for a lighter, handier and quieter weapon for specialist and even closer-quarter use. To that end, he reportedly designed and built two .22 inch rim-fire calibre prototypes along the same lines as his .45 calibre carbine. One was his own personal rifle, previously constructed for his own use, and a second may have been a further example for submission to the investigating authority. Although these small-bore weapons undertook basic trials, it is not known whether they may ever have seen action, but this prospect is unlikely, although not entirely impossible. One example remained in the care of the Imperial War Museum after the second World War, and was subsequently passed to the National Army Museum.

We are able to show images of Geoffrey deLisle's own .22RF carbine, which arm was retained by him for many years prior to its being handed by a generous purchaser to the National Army Museum for safekeeping. Sadly, all that is now publicly available to researchers is this pair of photographs, by kind permission of the Museum's trustees. The whereabouts of this carbine, let alone the other supposed example, are now uncertain.

The .22RF carbine was hand-built on the action of the ubiquitous Browning semi-automatic sporting rifle. A fairing-piece was added, below the forward part of the action, possibly to support the rear of the fore-end and to protect the cocking-piece's modified and protruding operating flange in the ejection port. It is fastened to the front of the trigger-guard with one lateral machine-screw. The rifle was especially stocked with high-quality walnut and the fore-end and pistol-grip finely chequered. A pair of figure-of-eight style split mounting brackets supported a telescopic-sight believed to be a German "Fuess" model, not unlike those from the Evans stable occasionally fitted to the Pattern '14 Enfield No.3T sniper rifles used in the First World War. Many of these latter rifles and scopes saw service early in the 1939-45 War, but such telescopes as these had also been sold both commercially and as war surplus between the two major conflicts.

Below are two outline and sectioned drawings associated with the specification for the SMLE based .45 calibre de Lisle carbine and its patent.

An apocryphal tale of one trial of the first deLisle prototype is that the urgently required new weapon was completed overnight and taken to the London building of the Special Operations Executive (S.O.E.) first thing the following morning. Impatient to discover its capabilities, it was test-fired at pigeons on the roof of a building opposite. So quiet was the report, in the early part of the wartime "rush hour", that there was no reaction from passers-by. How the pigeons reacted was not reported; and neither is there any indication of concern for the fall of shot. One should perhaps remember that significant quantities of metal of all types were then falling from the skies over England, and the odd .45 calibre pistol round, on a decaying trajectory, even had it been spotted, may barely have raised an eyebrow. Health and safety considerations were at the time hardly in the fore-front of general thinking.

However, as with many such anecdotes, there is an element of truth in the above story, but the veracious, and only marginally less thought-provoking version, came from the horse's mouth. Interviewed by Mr. Ian Skennerton in 1981, William de Lisle related how during early "field-testing" of the suppressed carbines, they were fired at a large chimney across the road from the Wilkes gunsmith's premises near Piccadilly where prototyping was taking place*. The discharges were thereby proven to be "imperceptible" to those passing in the street below; the possibility of heavy hail notwithstanding!

The carbine is reported to have been immediately despatched to the continent for further assessment (perhaps even a practical trial), and further examples ordered on the spot.


See also the Enfield Rifle No.4T sniper training rifle


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