As reported Sept. '00 in SWAT Magazine:
CLANDESTINE 12
Silenced Shotgun from Tac Ops
by
Eugene Nielsen
Cover photo by Stan Nielsen
The 12 gauge shotgun can be one of the most versatile and effective tools in the tactical arsenal. Unfortunately, it has two big drawbacks -- it has one heck of a muzzle blast and has an enormous muzzle flash. These drawbacks often outweigh the shotgun's utility in many tactical scenarios.
The blast and flash can be a serious liability. A standard shotgun is hardly a covert tool. When employed for breaching, the sound of the shotgun’s discharge can lead to “they shot first” scenarios. The muzzle flash of a shotgun can significantly impair night vision and give away the operator’s position. The flash can be downright lethal to the operator when operating in explosive environments, such as when raiding clandestine drug laboratories.
The Science of Silence
There are three possible sources of sound from the discharge of any firearm that need to be considered when “silencing” a firearm: the weapon’s muzzle blast; the sonic boom caused by a projectile exceeding the sound barrier; and the sound from the cycling of the firearm’s action.
The muzzle blast is the most significant source of sound. Muzzle blast is the consequence of high-pressure gasses suddenly exiting the barrel. If the pressure is reduced immediately before it exits, the weapon’s report will also be reduced.
There are several ways that pressure reduction can be accomplished. Pressure can be reduced by increasing the volume of space occupied by a given quantity of gasses. It can also be reduced by decreasing the temperature of the gasses and/or delaying the exit of the gasses by creating turbulence and trapping the gasses. The effectiveness of a suppressor in reducing muzzle blast is dependent on how well it achieves these objectives.
Muzzle blast is also reduced by decreasing the velocity of the gasses and either absorbing the sound waves or canceling them by interference with reflected waves coming from the same source. The behavior of sound waves is similar to that of light waives in many respects. As with light waves, sound waves can be reflected, refracted, diffracted and scattered.
Various combinations of components (such as baffles, packing material, mesh, expansion chambers, spiral diffusers, pressure relief ports and wipes) may be employed in a sound suppressor. Artificial environment technology or “wet technology,” as it’s commonly referred to, may also be employed. Wet technology employs greases, oils or other fluids to cool the gasses for more effective sound suppression. The use of wet technology increases the efficiency to size ratio of the suppressor.
A Difficult Task
There have been numerous attempts to silence shotguns and eliminate their muzzle flash. The large bore diameter of the 12 gauge shotgun has been the major impediment to the development of an effective sound suppressor. Conventional sound suppressor designs of a practical size have allowed too much gas to escape to effectively silence the weapon.
A lesser but still significant problem has been the fact that most shotgun loads are supersonic. If a projectile exceeds the speed of sound (about 1,087 feet per second (fps) at sea level), it will “crack” as it passes or the sonic boom is reflected back from a hard object. This miniature sonic boom can be quite loud.
As a result of the problems in effectively silencing a shotgun firing conventional shotgun cartridges, the US Navy decided to try a different approach. In 1967, the Navy announced a requirement for a silent shotgun cartridge that could be fired from unmodified, conventional military shotguns. Although this may have seemed like an impossible task, AAI Corporation did in fact come up with such a cartridge, based on their patented Telecartridge™. Intended for use by Navy SEAL and Marine Recon teams, the Silent Shotgun Shell has to be one of the most unusual cartridges ever developed.
The AAI Silent Shotgun Shell utilized an explosive propellant under a folded, steel Telecartridge cup. When fired, the expanding gasses extended the cup. The payload, consisting of 12 #4 buckshot was expelled by the initial impulse. The sealed Telecartridge cartridge cup contained the gasses, flash and most of the noise.
The Silent Shotgun Shell was a great idea, but it too proved impractical. To prevent the Telecartridge from rupturing, the muzzle velocity of the round had to be reduced to just 450 fps. The low velocity resulted in a short range cartridge of limited lethality. This coupled with the high cost of the rounds caused the project to be dropped after only 200 test rounds were delivered to the US Naval Ordnance Testing Laboratory.
The Clandestine 12 Suppressed Shotgun
Recognizing the tactical need for a sound- and flash- suppressed shotgun, Mike Rescigno, President of Tactical Operations, Incorporated, set out to develop just such a shotgun. While well aware of the failures of others before him, he believed that a practical sound suppressor for shotguns was possible. After four years of extensive research and development, Tac Ops has achieved what has eluded others.
Tac Ops discussed the design of the suppressor in considerable detail on the condition that I not reveal any of the specifics. Suffice it to say that it’s very innovative. The suppressor utilizes an advanced, patent-pending design with proprietary artificial environment technology to provide performance that was previously unattainable. According to Tac Ops, the suppressor will safely handle all commercially loaded 12 gauge ammunition.
Called the Clandestine 12™, the sound suppressor has a stainless steel body and heat-treated aircraft-grade aluminum internal parts. Considering that it’s designed to suppress a 12 gauge shotgun, the suppressor is exceptionally compact. The suppressor measures 10 inches long and has an outside diameter (O.D.) of 2.75 inches.
The suppressor does add a significant amount of weight to the muzzle. The Clandestine 12 suppressor weighs approximately 3.75 pounds. For those who may be concerened about the weight, Tac Ops is currently working on a prototype of a lighter suppressor that is quite revolutionary.
The suppressor is a sealed unit and is designed to be user maintainable. All maintenance requirements are performed without disassembly. Cleaning is by immersion. Petroleum naphtha (safety solvent) is recommended for this purpose.
The Clandestine 12 package is built around the a customized Remington Model 870 shotgun. The Remington 870 is the most widely used police shotgun. As with all of Tac Ops weapon systems, the attention to detail on the Clandestine 12 is superb.
All of the metal parts, except for the bore and chamber are finished in Walter Birdsong’s proprietary mattte NATO Green-T® and Black-T® finish. Birdsong’s finish was developed specifically for use on weapons. It’s highly wear resistant and has excellent corrosion resistance and lubricity. Widely regarded as the best finishish of it’s type, it’s specified by the FBI HRT and numerous government agencies.
The Clandestine 12 is supplied with two barrels: a standard Remington 18-inch cylinder-bore barrel and a 14-inch barrel with the Clandestine 12 sound suppressor permanently attached. The suppressed barrel has a 21-inch overall length. A Wilson Combat ® / Scattergun Technologies magazine extension tube is supplied for the standard barel...
