The De Lisle "Commando" carbine
page still partly under construction
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 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 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 recess drilled to accommodate a rubber 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.
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, bell-mouthed, 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 twenty rounds.
The conversion consisted of removal of the .303 calibre rifle barrel and magazine followed by replacement with a bell-mouthed modified .45 calibre Thompson sub-machine gun barrel 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 9 mm 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 a drilling 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 are 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 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 designed and built at least two .22 inch rim-fire calibre prototypes along the same lines as his .45 calibre carbine. Although these small-bore weapons undertook basic trials, it is not known whether any went into action, but this prospect is 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. Images will be brought to this page as soon as they have been obtained.
Below are two outline and sectioned drawings associated with the specification for the de Lisle carbine and its patent.
See also the Enfield Rifle No.4T sniper training rifle
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