Bolt Action, Integrally Suppressed, .45 ACP, Special Operations Carbine
The suppressor was invented by the son of Maxim Machine Gun creator Sir Hiram Stevens Maxim. Hiram Percy Maxim developed the suppressor in tandem with the first ever muffler for internal combustion engines. The suppressor was patented in 1909, just 24 years before William Godfray De Lisle created a prototype for his quiet, quiet, carbine.
How Do Suppressors Work?
Suppressors redirect the propellant gas that forces a bullet down and out of a barrel. This gas is comes from the explosion of the gunpowder behind the bullet. Suppressors have a series of baffles that create a maze for gas to travel through, reducing energy and therefore sound. They do not work as well as the movies might have you think. Some calibers, such as .22LR and .300BLK can be so quiet that the only noise you’ll hear is the action cycling, but this is fairly rare. Most noise reduction is just good enough to eliminate the requirement for ear protection.
How Does Integral Suppression Work?
Integral suppressors work the same way that screw-on suppressors do. Rather than creating an extension to the barrel through which the bullet must travel, an integral suppressor covers the barrel, which is shorter than the integral suppressor shroud. This reduces the overall length of a firearm and can increase effective decibel reduction, especially in bolt-action guns. On the right is an original design drawing for the De Lisle.
The Second World War saw the development of many weapons still in use today. With an incredible variety of battlefield needs, the conflict bred an astonishing number of strange guns, armor, submarines, boats, and planes. The De Lisle was created in the spirit of the Welrod pistol, and became useful for commandos who needed to stay quiet while on dangerous missions in enemy territory. The UK’s long history with suppressors led to a modern culture in which they are not regulated, and in which it is even considered bad manners to shoot or hunt outside without them!
William Godfray De Lisle was an engineer working for the Air Ministry during WWII. He had the idea for an ultra quiet firearm, and toyed around with it on his own time in 1942. His original design was chambered in .22LR. Godfray put it together by modifying a short version of the magazine-fed Lee-Enfield Mk III. When De Lisle decided to formally introduce his prototype in 1943, he approached Sir Malcolm Campbell, a race car driving military policeman in charge of rescuing Queen Elizabeth in the event of a German invasion. Campbell tested the carbine by firing it into the Thames off the roof of the Adelphi Building. He wanted to know if pedestrians would be aware of the gunfire above them: they were not. Campbell requested a 9mm version in order to beef up the De Lisle for combat applications. That second prototype didn’t work out, but De Lisle found that the venerable big-and-slow .45ACP was perfect for the job.
The third De Lisle used a modified Lee-Enfield Mk III action, bolt, and stock, a Thompson sub machine gun barrel, and modified 1911 magazines. Later versions with folding stocks were developed for paratroopers. This frankenstein produced no muzzle flash, and was inaudible at 50 yards. Early firing tests produced 85.5db of noise, which is just about 10db louder than your average vacuum cleaner. The De Lisle was 80db quieter than a non-suppressed handgun, and 32 – 55db quieter than handguns suppressed with an attached unit. Perhaps the most important element in the success of the De Lisle was the massive chamber around the barrel (integral suppressor). The volume of that space produced both the quietness and the flash suppression that would later inspire H&K in their production of the MP5SD. The De Lisle carbine was so quiet that cycling the bolt was louder than actually firing a shot.
Specialty Interest Arms
The De Lisle reproduction pictured here was created by SIA on a genuine Lee-Enfield Mk III. SIA specializes in integrally suppressed guns, but have ended their run of De Lisle reproductions. This is not an exact reproduction, you’ll notice the 1913 rail. Inspired by the De Lisle, the “Enfield .45-SC” is damn close, and looks like a ton of fun.