Suppressed rifles, also commonly known as silenced rifles, are firearms equipped with a device called a suppressor or silencer. This device is often attached to the barrel by threads or a quick-detach adapter. It reduces the amount of noise and visible muzzle flash generated by gunfire. The term "silenced" is a misnomer since the sound of the projectile exiting the barrel is still audible but the noise signature is drastically reduced. Let's talk about how you can reduce the sound signature of your AR-15 rifle with a suppressor device. Remember that suppressors are Title II weapons and restricted NFA items under the Gun Control Act of 1968. You must meet all requirements to possess and own these devices.
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Introduction to Suppressed Rifles
A suppressor does not completely silence a firearm despite the popular belief and Hollywood portrayals of silenced guns. You may often hear these types of guns sounding like a "pew pew pew" in movies where they are often a pistol or rifle wielded by an assassin-like character or live action hero. In these fictional settings, they sound kind of like a laser gun from Star Wars but much quieter.
In the real world with real steel suppressed guns, suppressors significantly dampen the un-suppressed report to a safer and more manageable level. However, they still sound like a gun with a loud "teeesshhh teeesshhh teeesshhh" sound unless the shooter is also firing subsonic ammunition. Subsonic bullets, like a CCI sub-sonic 22 LR round, prevent the bullet from breaking the speed of sound at under 1,080 FPS and make a "tssk tssk tssk" sound when fired.
Suppressed rifles are often used for hunting, competitive shooting, and law enforcement because of their benefits in noise reduction, recoil minimization, and ability to reduce the shooter's location visibility. However, suppressors are an NFA item meaning they are regulated by the National Firearms Act of 1934 in an effort to control the potential misuse and register who owns which suppressor unit. Their accessibility to the general public is often regulated by strict laws and regulations.
How do suppressors work when a bullet is fired out of a gun?
Suppressors work on a simple principle of disrupting the gases released at the breach (end) of the barrel when a gun fires a bullet. Every gun releases hot gases which propel the bullet out of the firearm at high pressure when the trigger is pulled. It is this release of gases that makes the loud sound commonly associated with a firearm being discharged.
When a suppressor is attached to the distil barrel of a gun opposite the shooter, it works to cool down and spread out these gases before they leave the barrel. The suppressor is essentially an expansion chamber with a series of breaks and partitions known as baffles inside. The hot gases from the firing bullet enter this chamber, bounce against these baffles back and forth, lose their energy, dissipate temperature, and reduce the exiting pressure.
This process muffles the sound of the firearm significantly. However, as we discussed earlier, it's important to note that the sound is not completely eliminated and movie portrayals are highly exaggerated. Real suppressors only reduce the sound level enough to protect the shooter's hearing from damage and partially mask their location. They do not make a gun virtually silent.
The technology behind these devices was developed in the early 20th century and remains a focus for continual advancements in firearms science. New materials including carbon fiber, aircraft grade aluminum, and 3D printing technologies are under development to make suppressors more effective, last longer, and more cost effective.
U.S. Patent Application Pub. No.
US 2013/0180150 A1
This gun accessory also has several elongated spikes that extend in a forward direction from the base, arranged in a circle around the accessory's centerline. Further, the gun accessory includes a hole that is essentially centered around the centerline. The gun accessory has three longitudinal slots formed by the walls between each spike, which is designed to let combustion gases flow from the hole. The walls stretch from the hole to the attachment's outer surface. Walls of neighboring spikes are located in individual planes that intersect at an angle ranging from roughly 9 degrees to about 12 degrees. Other versions and associated methodologies are also included.
Source: Barry W. Dueck; Surefire LLC assignee. FIREARM ATTACHMENT. United States Patent US 2013 018O150A1, May 4, 2012, July 18, 2013.
Suppressors for AR-15s
Choosing the best suppressor for your AR-15 rifle comes down to understanding the round your rifle is chambered in, suppressor build, and your ability to register the NFA item.
About AR-15 Cartridges
The AR-15 rifle is a versatile and widely used weapon. It is the semi-auto civilian counterpart to the military's M4 rifle which is often burst or full-auto capable. The AR-15 shooting platform can accommodate a range of cartridge types depending on how it is chambered. The most common cartridges used in these firearms are the .223 Remington and the 5.56x45mm NATO rounds.
- .223 Remington: The .223 Remington, a civilian round with lower pressure than 5.56, was the original cartridge for which ArmaLite designed the AR-15. It's known for its precision and lower recoil which make it easier to fire multiple rounds in rapid succession. This makes AR-15s ideal for varmint hunting, target shooting, militaresque training, and law enforcement.
- 5.56 NATO: The 5.56x45mm NATO cartridge is the military variant and has slightly higher pressure than .223, resulting in a little more power—making it suitable for both civilian and military use. The NATO rounds are often used in competitive shooting events because they comply with most event regulations. An important consideration is that while 5.56mm rounds can be safely fired from a .223 Remington chamber, the reverse can be unsafe due to pressure differences. Therefore, it is crucial for shooters to understand the compatibility of these cartridges with their AR-15 rifle.
Other less common rounds include the 6.5 Grendel, 6.8 SPC, .300 Blackout and variants like the .224 Valkyrie and .22 Nosler.
- 6.5 Grendel: The 6.5 Grendel round is a type of intermediate rifle cartridge designed specifically for the AR-15 platform, known for its long-range accuracy and ballistics. Developed by Alexander Arms, the 6.5 Grendel was created to improve upon the performance of the standard .223 Remington or 5.56mm NATO rounds, offering an impressive balance between velocity and bullet weight. It delivers incredible accuracy at a distance that significantly exceeds that of traditional AR-15 cartridges. The Grendel round utilizes a 6.5mm bullet typically known for its top-notch ballistic coefficients and sectional densities which help it can maintain a flat, straight trajectory over long distances with less recoil than larger calibers.
- 6.8 SPC: The 6.8 SPC is a rifle cartridge that was developed with the intention of improving the close-quarter and medium-range performance of United States Armed Forces' M16 rifles, carbines, and light machine guns. It was brought to life by an alliance between Remington Arms and the U.S. Army's Marksmanship Unit, United States Special Operations Command. The fundamental aim was to bridge the gap between the 5.56mm NATO and 7.62mm NATO rounds. The 6.8 SPC was created with enhanced kinetic energy, accuracy, and terminal performance in mind. It fires a .277" diameter bullet with weights typically between 85 and 140 grains, resulting in greater ballistic effectiveness on target.
- .300 Blackout: The .300 Blackout, also known as .300 AAC Blackout or .300 BLK, is a cartridge designed specifically for the AR-15 platform. Developed by Advanced Armament Corporation (AAC), it was introduced in 2011 to fill a specific niche in the firearms market. It was created with the aim of achieving ballistics similar to the 7.62x39mm cartridge used in AK-47s, but in an AR-15 platform with minor modification to the firearm. It is commonly used with suppressed AR-15s since the subsonic .300 Blackout rounds much quieter than 5.56.
Assault Rifle Suppressors for Different Calibers
When suppressing these common calibers, choosing the correct suppressor is mandatory. The suppressor's constructor and materials are often built to accommodate specific pressures and gasses. They also come in different come in different lengths and sizes to work with various calibers. While intended primarily for .223/5.56 caliber rifles, AR-15 suppressors can also accommodate handguns and other rifles of different calibers such as .300 Blackout or 6.5 Grendel.
When selecting a suppressor, it's crucial for shooters to match the accessory to the specific caliber of their firearm to ensure compatibility and maximize effectiveness. Features like decibel reduction, attachment, weight, length, and material durability are typically considerations when choosing a suppressor.
- Suppressor Function: The suppressor decibel rating measures the degree of sound reduction accomplished by the suppressor or silencer. This is dependent on the baffle design and materials. When a shot is fired, the loud "report" sound is generated due to gases rapidly expanding from the ignition of gunpowder. The suppressor begins working at that point by controlling these gases, containing them within the baffles, and diffusing them before the gasses leave the silencer cylinder. This reduces the volume of the gunshot.
- Suppressor Decibel Rating: The decibel rating of silencers often range between 20 to 40 dB. The higher the rating number, the more sound the suppressor eliminates. However, it's important to remember that achieving a 0 decibel rating is impossible as it implies absolute silence. 0 dB isn't practical even with the most advanced suppressors due to mechanical and ambient noise. Choose a suppressor decibel rating based on the ammo you plan to use (subsonic versus supersonic) and the environment you are operating the weapon system in.
- Suppressor Material: Most suppressors are usually made from titanium or stainless steel alloys which are resistant to extremely high heat. The material a suppressor is manufactured from affects the lifetime, durability, and weight of the suppressor. The size and weight of the suppressor also impact its handling and gas dissipation qualities. You get what you pay for in the world of silenced weapons with some of the best 5.56 suppressors like the SureFire SOCOM556-RC2 running over $1,000.
- Suppressor Attachment: The method of attachment to the Ar-15 is significant as both direct thread and quick detach systems have their pros and cons depending upon the operator's preference. Choice of the suppressor attachment also depends upon the specific use, whether it is for hunting, home defense, or law enforcement or other tactical purposes. For example, if you are moving in and out of vehicles or confined spaces, having a quick-detach suppressor is very useful to reduce the overall length of your weapon system as you move and transition.
NFA Suppressor Guidelines
Suppressors and silencers are qualified as National Firearms Act (NFA) items. The NFA provides specific guidelines for the use and ownership of sound suppressing devices in the US. First off, to legally possess a suppressor, one must obtain approval from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). This process includes a comprehensive background check, fingerprint card, and a special tax stamp payment ($200). It should be emphasized that the use of such devices is heavily regulated in many jurisdictions due to their potential misuse. Therefore, buyers must ensure they comply with local laws, obtain necessary permits, and register the device with the appropriate authorities.
The suppressor must be registered to the owner and is typically marked with a serial number for identification. It is also worth mentioning that not all U.S. states permit civilians to own suppressors, and those that do often have additional regulations in place. For instance, some states stipulate that suppressors can only be used for hunting or specific use cases. Additionally, the use of suppressors is banned in certain public places. Misuse or violation of the NFA suppressor guidelines is considered a federal offense, punishable by heavy fines or imprisonment. Be sure to know and understand all of these guidelines before buying and using a suppressed AR-15.
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