The British De Lisle Commando Carbine
By Frank Iannamico

The silenced .45 caliber De Lisle Carbine was conceived as a weapon for special operations where a target could be eliminated without attracting the attention of enemy forces in the area.

During World War II, William Godfray De Lisle lived in Southern England. An engineer and firearm enthusiast, he built a silencer for his .22 caliber Browning semiautomatic rifle, primarily to quietly hunt for game to feed his family. A neighbor who had heard about the silenced rifle was British Army Major Sir Malcolm Campbell. Major Campbell contacted De Lisle and proposed that he demonstrate his silencer to officers of the Combined Operation Executive in London. The officers were impressed with De Lisle’s design and suggested that a similar weapon be made in 9mm. A second prototype was built in 9mm, but the velocity of standard 9mm cartridges exceeded the speed of sound making a loud crack when the bullet broke the sound barrier. A barrel vented to reduce the velocity of the 9mm round to subsonic speed reduced the round’s effectiveness. De Lisle then suggested using the .45 ACP round for the weapon. The cartridge was already in British service, used in both the Thompson submachine gun and 1911 pistols. The .45 caliber cartridge was chosen for the project because of its inherent subsonic velocity and documented stopping power.

Major Campbell took De Lisle’s drawings to the armorers at Bapty & Co. (a firearms rental company for the film industry) and asked them to build the first .45 caliber De Lisle carbine prototype using the barrel from a Thompson submachine gun and receiver from an Enfield rifle. The concept of the silenced carbine was then proposed to the British Ordnance Board. After testing and evaluation, the concept proved successful. Because the carbine was a special project for Combined Operations Headquarters, the usual bureaucratic red tape was avoided, and an order was initiated for immediate production.

The first seventeen production De Lisle carbines were assembled in 1943 from unserviceable Mk 1 No. III SMLE Enfield rifle receivers at the Ford Motor Company, Dagenham, UK. The rifles were modified by adapting a modified .45 caliber Thompson submachine gun barrel, shortened to 7.45 inches to the Enfield’s receiver. Because the new barrel extended into the receiver approximately 2 inches, the Enfield’s bolt had to be shortened, the bolt face was recessed, and a new extractor designed for the .45 ACP round’s rimless case. A new longer cartridge ejector was designed and fitted to the left side of the Enfield receiver. The charger bridge and magazine cutoff were removed from the receiver. The opening for the original magazine was covered with sheet metal, and a magazine housing was fabricated to accommodate a .45 caliber U.S. 1911 pistol magazine. The 1911 magazine was altered by adding a rib similar to that of the original .303 caliber magazine to use the rifle’s original magazine catch. The Ford suppressor tubes were made of steel, approximately 15 inches in length, and 2 inches in diameter. The internal components consisted of an expansion chamber and thirteen baffles held in alignment by two rods and spacers were used to separate the baffles.

The Ford carbines were tested by the British Ordnance Board for reliability, stealth and accuracy. The De Lisle carbines were compared to a suppressed 9mm Sten Mk2 (S). The sound level of the De Lisle was determined to be satisfactory, and there was no muzzle flash. The De Lisle had the advantage of being a bolt action weapon so when fired there was no noise from the action cycling as in the open bolt operated Sten. The suppressed Sten used standard issue 9mm cartridges, to reduce the rounds to subsonic velocity the weapon was fitted with a ported barrel that dispersed some of the gas pressure propelling the bullet.

After the successful fielding of the Ford carbines, a contract for 500 De Lisle carbines was placed on 16 November 1944. The last 50 were to be airborne models with pistol grips and folding buttstocks. Production would take place at the Sterling Engineering plant. The production De Lisle differed slightly from the early models made by Ford. The suppressor tube was 2 inches in diameter, 15.75 inches long and made of aluminum. The modified Thompson submachine gun barrel had a series of small holes drilled near the muzzle to vent some of the hot gas into the expansion chamber. There were 13 baffles placed ahead of an expansion chamber. The baffles were made of duralumin, an alloy of aluminum containing traces of copper and magnesium. The first two baffles were flat; the following eleven baffles were larger in diameter and had a vertical cut at the top that extended into the bore hole. The metal on each side was bent in opposite directions. The muzzle did not extend past the end cap on production models. The end cap was secured with two Allen head screws. An 8-inch wooden forearm was fitted under the suppressor tube. Webb and Company, who had supplied Sterling with Lanchester rear sights, provided a number of the early-style Lanchester sights re-calibrated and marked for a range of 50 to 200 yards. The sight was riveted to the top of the suppressor tube. The front sight was a fixed blade protected by two large “ears.” The sight radius is 12.25 inches. Some carbines were fitted with luminous night sights provided by the firm of Holland and Holland. To deaden the sound made by closing the weapon’s bolt, a synthetic material was placed into a machined area under the bolt handle where it contacts the receiver. A De Lisle carbine weighs 8 pounds, 14 ounces loaded, overall length is 35.75 inches. In addition to the standard 7-round pistol magazine there was an 11-round magazine produced.

The De Lisle carbine was fielded during commando operations in France prior to D-Day and behind enemy lines after the Allies successful landings in Normandy. The De Lisle had also proved even more effective against Japanese forces in the Pacific Theatre during fighting in jungle environments. Reportedly, the De Lisle continued to see service after World War II had ended.

On 20 December 1945 the De Lisle contract was cancelled before the 500 carbines originally ordered were delivered. The actual number produced is subject to some conjecture. One source states that 106 were completed, but a few more were assembled after the contract ended for an estimated total of 130. The number of De Lisle carbines manufactured is sketchy at best due in part to its adoption and manufacture largely being a secret affair. Serial numbers have been observed up to the range to indicate manufacture consistent with this. However, there does exist one example with the number “209” in a UK reference collection, and this number is placed in the well in front of the bolt handle like the other De Lisle serial numbers. Further clouding the issue was most of Sterling’s De Lisle production records were lost in a fire caused by a German V rocket attack adding to the mystery.

Despite their small numbers, the De Lisle is well known among martial arms collectors. An original example would be worth a good deal of money, thus it has attracted the attention of those who assemble reproductions and attempt to pass them off as originals.

Modern De Lisle Carbines and .45 Caliber Enfield Conversions

There have been several companies in the U.S. that have assembled replica De Lisle carbines. Faux non-functioning suppressors were usually available as an option for those living in areas where suppressors were prohibited or those individuals not wanting to pay the additional $200 transfer tax.

During 1983, Gary Delsignore built a small number of De Lisle carbines fitted with faux suppressors. To remain legal the barrels were 16 inches in length.

While not specifically intended to build a De Lisle replica, a company called Rhineland Arms offered kits to convert Enfield rifles to .45 caliber.

Century Arms sold a number of No. 4 Enfield rifles converted to .45 caliber.

The former Valkyrie Arms, Ltd. of Olympia, Washington produced a very close copy of the De Lisle before going out of business. The Valkyrie clones were available with a functional or dummy suppressor. Reviews on the quality of the Valkyrie De Lisle builds have been mixed. Serial numbers have been observed into the 150 range.

The most recent manufacturer of a De Lisle clone is Richard Brengman of Special Interest Arms (SIA), a company that specializes in Enfield rifles offering parts and accessories to restore or update the rifles.

The Special Interest Arms De Lisle is not an exact copy of the original, something that is readily admitted by the company in their advertising. One of the most obvious non-original features is the large magazine well that has the same profile as an original .303 Enfield magazine. The SIA conversion allows the use of an original, unmodified 1911 pistol magazine. The SIA magazine adapter positions the magazine closer to the rifle’s barrel and eliminates the need to shorten the bolt as was done on the original De Lisle. Feed and extraction are said to be improved over the original, the barrel’s chamber is fully supported in the receiver and McGowen Precision premium barrels are used to ensure accuracy. The ammunition charger guide has been removed as was done to most originals. The baffles are the same configuration as the originals, but made of stainless steel, which is an improvement over the original baffles made of duralumin. The company plans to offer a modern monocore baffle system as an option. The silencer tube is 16 inches in length and integral to the action so that only one NFA tax is required. As on the original, an insert is placed in the underside of the bolt handle to suppress any noise when the action is closed. The SIA insert is made of a modern material called Delrin. Except for the magazine adapter, the outward appearance is very faithful to an original. Overall quality, fit and finish, of the SIA replica are excellent. The loaded SIA De Lisle weighs 9 pounds, 10 ounces, overall length is 35.75 inches. The 16 inch steel suppressor tube has 13 baffles. Like an original De Lisle suppressor the SIA version has an expansion chamber. The first two baffles are flat and the remaining eleven are split at the top and tabs are bent in opposite directions.

In addition to the De Lisle replica, Special Interest Arms offers kits to convert Enfield rifles to .45 caliber, which includes a .45 barrel, ejector, 1911 magazine and magazine adapter.

Another suppressed rifle offered by SIA is the .45-SC, inspired by the World War II De Lisle silent carbine, but built on a No. 4 action using a concentric tube and modern "M" baffles. The .45-SC is available with wood or a black synthetic stock.

Firing the SIA De Lisle

As advertised, the SIA replica De Lisle is very quiet, due in part to its large volume suppressor. Despite its relatively short barrel, the carbine is also accurate easily able to print 1.4 inch groups at 100 yards. Several different brands of .45 ACP, 230 grain FMJ cartridges were used in the test. Feeding and ejection was flawless during firing of 200 rounds during the evaluation. Firing a steel target was especially enjoyable. The report of the carbine was minimal compared to the sound of the big .45 caliber slug striking the steel. As a platform for firing .45 caliber rounds the carbine is heavy and felt recoil light.


Special Interest Arms
Richard Brengman
1422-A Industrial Way
Gardnerville, NV 89410
(775) 783-4867

This article first appeared in Small Arms Review SAW (May 2013)
and was posted online on April 12, 2013


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