I have had some many people ask me about the NFA as of late, and for explanations about SBRs and most of all about silencers that I put this together to literally just email and hand to people... I wanted to share it here and I know when I was getting into the NFA world something like this would have been somewhat helpful. This could be way more detailed but in all honesty there will still be questions. This is just to help people understand and then ask the right questions so when an answer is given they understand and can be guided but still make an informed decision on their own.
Joining the NFA (National Firearms Act) world: This means silencers, short-barreled rifles, shotguns, and even machine guns!
There is a lot of vernacular you will need to know when entering the NFA world in order to avoid confusion but you can also learn as you go like many others have. Some detail will be given here but nothing too deep.
Tax stamp- this is what you will receive back when the ATF has processed your paperwork and you can now take possession of your NFA item. It costs $200 and it is paid for when you submit your paperwork.
Jail- this is the time period you wait from the time that you file your paper work until it “gets out of jail” and you get to take it home.
Individual- a person may choose to have their NFA item transferred to a single individual this is beneficial as only that person is responsible for any paperwork
Trust- a NFA trust may be used by an individual to transfer a NFA item. When a NFA item is in a trust, all members of the trust have access of use to the NFA items it holds. This is beneficial for many reasons in the use of the items, as well as it allows for beneficiaries to be named in the event of death. The only draw back is all parties in the trust are responsible for some paperwork such as fingerprinting, photographs, and signatures.
Form 1- this is the form you file with the ATF to manufacture an NFA item. This can be used for silencers as well as short-barreled rifles and shotguns (not machine guns).
Form 4- this is the form that is filed with the ATF to transfer a NFA item to an individual, corporation, or trust.
Form 3- this form is used to transfer NFA items between dealers and distributors. You will commonly hear this if a dealer must order in a silencer for purchase, or on the new release of a new product.
SBR- Short Barreled Rifle. A rifle with a barrel less than 16” in length.
SBS- Short Barreled Shotgun. A shotgun with a barrel less than 18” in length.
Silencer- a device put on the muzzle of a firearm, to reduce the sound, and even flash signature of it. Also commonly referred to as suppressors, cans, and even mufflers. All terms are correct and are interchangeable.
Transferables- machine guns registered prior to May 19[SUP]th[/SUP] 1986 that are able to be owned by anyone however there are less than 200k and due to supply and demand their value continues to go up dramatically.
Post-Samples- Machine guns made after May 19[SUP]th[/SUP] 1986. They are for dealers, manufacturers, military, and police.
Sears- these are commonly called auto sears. There are a few different kinds, but they can be used with firearms such as an AR-15, or HK, which then gives the user a “fun switch” which is a term of endearment for full auto capabilities via the selector.
Short Barreled Rifles (SBRs) and Short Barreled Shotguns (SBSs)
You can buy a short-barreled rifle or shotgun directly from a dealer on a form 4. This is an option many choose so that they have a factory gun or because making the changes themselves is a hassle or not extremely practical which will now be discussed.
It is very common for people to obtain the firearm they wish to have as a SBR or SBS first in either pistol form, or with a 16” or longer barrel as a non-NFA item. When they have the firearm they will them submit a Form 1 to the ATF and await approval. This is also because the firearm is never in “jail” and it is in a person’s possession from day one. When the wait is over and the individual has received their tax stamp, they may then simply add a stock to the firearm if it is in pistol configuration, or have the barrel cut down to the desired length if the firearm was a non-NFA item originally due to barrel length.
Another important step in the form 1 process is that the item must be engraved with the manufacturer information. This would be the name of the individual or trust which filed the paper work, followed by the city and state of residence.
It is very common to form 1 a AR lower due to the fact at that point you can place any upper on it you wish with a barrel of less than 16” this is due to the fact it can always be converted back to it’s original length.
Silencers
Silencers can be manufactured on a form 1, but it is most common to purchase them from a dealer on a form 4. This is where you will most commonly hear people talk about things in jail. When you purchase a silencer from a dealer the dealer should then help you submit the form 4 and in many cases take care of most of it for you. It is at this point you will wait for approval. Upon the return of your tax stamp to the dealer, the customer is contacted and may come pick up their item upon completion of a 4473 (NICS background check).
Which Silencer is right for you??
The big question is what do you want out of the silencer? Many want the quietest silencer they can get, others want something that is light weight, the most durable, something that suppresses the most calibers possible, and the list goes on. Hearing safe levels are said to be anything that is 140 decibels or under. Many things come in to effect when suppressing a firearm and the level of suppression one will get which will be discussed.
There are many features the consumer must consider and perhaps rank in order of importance so they may choose the can that best serves their needs. It is not possible to have it all.
Suppression- amount of decibels the silencer reduces the sound signature. Most all silencers on the market are hearing safe with exceptions made when very short silencers began to be used on short barrels or very large calibers. However, some silencers are quieter than others. There are a few trade offs for better suppression but the largest is a longer length.
Subsonic and supersonic- subsonic and supersonic have to do with the speed of sound. Something traveling slower than the speed of sounds is subsonic where as something traveling faster than the speed of sound is supersonic. With suppressors this pertains to bullet speeds and sound. When something is traveling faster than the speed of sound a sonic boom takes place. For this reason when some rifle and pistol rounds leave a barrel a sonic boom occurs. The speed of sound changes based on your elevation but it generally ranges from 1,100ish feet per second on down as elevation increases. When a sonic boom occurs it puts a large crack out in to the air. This is not the gun making the noise or the silencer failing to suppress the gunshot but rather the projectile traveling through the atmosphere creating the noise. This is important because depending on what guns are being shot and the ammunition going through them the amount of noise made will vary.
Silencer length- the length of a silencer is very important as it plays in to so many other factors. Silencer length affects the following things. Number one is the sound suppression, as the longer a silencer is generally the more decibel reduction it will yield. The overall length of the firearm a silencer is attached to sometimes make it more or less maneuverable. Weight is something to also consider, the more material you have the more it will weigh. Flash signature is a factor at which some may scoff or not give thought to, but the longer a silencer is the better it will reduce or even hide the flash signature or a firearm. Back pressure is also affected by silencer length, the longer a silencer is, the more it tends to increase the backpressure (read more below). And tone, many times short or long versions of the same suppressor will sound very different from one another. There is a modular trend however that is very popular in pistol cans, and can be found on some rifle cans as well. This is where the silencer essentially has two parts. There is a front module that can be added or removed to change the length thus affecting all of the attributes listed above; most importantly the overall length, weight, and amount of suppression. Short silencers will often be referred to as K cans. These cans are made to be shorter and lighter than what is usually a full sized version of it. While some suppressor users are very concerned with performance, others are more concerned weight, length and other listed variables as long as they are hearing safe. But one needs to consider barrel lengths (rifles) and other variables when making the right choice for them. There are many reasons to have both full sized as well as K cans.
Weight- the weight of a silencer can be very important for many reasons, you are hanging it off the end of your gun, and often carrying it around, holding it up to shoot etc. This varies in importance from person to person and with intended use. The build materials and size of the can are what most influences weight.
Build materials- Silencers are constructed from a wide range of materials. With few exceptions, there are two basic parts of a silencer, the outer tube, and the baffles stack or monolithic core inside of it. Some silencers feature individual baffles stacked together, and others feature a monolithic core where the entire system is one piece. However, the metal from which they are constructed is what really matters.
-Aluminum is common due to its lightweight nature, you will see it in 22 cans and with a few exceptions elsewhere.
-Chrome Moly Steel is a low-cost alternative that is ok for a lower volume of fire on longer barrels
-Stainless Steel is probably the most popular material used for baffles of which there are many grade that won’t be delved into. Stainless is durable, corrosion resistant, it’s not extremely expensive, and it holds up well to heat as well as hard chemicals. It is much easier to clean than aluminum if the can is serviceable.
-Titanium is lightweight and durable; it is often used where weight and precision are important. Unfortunately however, it is fairly expensive so silencers that feature titanium baffles tend to command a higher price. It isn’t uncommon to find complete titanium silencers, as well as silencers that have blast baffles (the first baffle in the silencer) that takes the brunt of the abuse that is a more durable material (see Inconel and Stellite). Then followed by all titanium baffles to make it as light as possible (this is sometimes seen with stainless steel as well).
-Inconel is a durable alloy that can handle extreme abuse and heat while not being terribly heavy. It is hard to work with but used to be the standard in durability, it can still be found but many companies have moved on from it
-Stellite is much more expensive than stainless steel but vastly superior to Inconel under the hardest use and conditions. Stellite has unparalleled hardness and toughness with a very high melting point, it also excels over other baffle materials in wear and erosion resistance. It is a great choice for short barrels and high schedule of fire, or any other abuse that someone may throw at it.
User serviceable- this is mainly important for rimfire cans as 22lr and other rimfire ammunition can be very dirty and it necessary for them to be cleaned from time to time. If a person wishes to shoot lead or cast pistol bullets it is also necessary to have a pistol can that is serviceable but in general it is not needed. Rifle cans for the most part are not serviceable and do not require any service.
Multi-caliber- many silencers on the market feature the ability to span a wide range of calibers. There are some that target this niche specifically. It is important to understand that one should always check with a manufacturer if they are unsure about a caliber and shooting it through their suppressor before doing so. Due to build materials, barrel length, and pressures of different calibers, certain cans may or may not be rated for a firearm you have.
With that said, as a general rule if it will fit through the hole it’s possible, but if the bullet is larger than the diameter of the silencer, you will simply destroy your expensive muzzle device.
What this means is that a shooter can shoot 223/5.56 through a .30caliber silencer without any issues, however the inverse would not be true. This is beneficial in part because a purchase of a .30caliber silencer can be made and cover all rifles from 223 all the way to 300winmag. This benefits the consumer because there is not any loss in performance shooting 223 through a 30caliber can over a caliber specific 223 can to speak of and some benefits such as lower back pressure are achieved. The same is true for pistols. Shooting 9mm through a 45caliber silencer suppresses just as well as a 9mm caliber specific can and then the shooter isn’t required to buy a silencer for every caliber they intend to shoot. Silencers in 30caliber, 45ACP, and 22LR will very effectively meet all needs.
Some companies have attempted to meet market demands for modularity by offering silencer than can be shot on pistols and rifles both. For example a silencer can be purchased to shoot 9mm, 22LR (serviceable) and all rifle calibers up to 300winmag, as the can has a diameter of .357 (9mm). Another example offering on the market offers the ability to shoot firearms ranging from from 9mm to 45ACP on pistols and 5.56 to 45-70 on rifles and everything in between (covering all 30caliber options). The only issue to consider with these cans is that they tend to make some compromises to achieve such a wide range of use and application. Many times the cans that are well designed for pistols do not perform as well on rifles. They also do not possess the ability to hold up to the schedule of fire can multi-caliber can would that was best designed for rifles. On the other side of that issue, a multi-caliber silencer that is well suited for rifles may be very heavy, bulky, and unwieldy hanging on the end of a pistol. They are however a great option for those certain they will not purchase multiple silencers.
Method of attachment-
Rimfire-most all rimfire cans are direct thread, however some QD (quick detach) options do exist mainly in the form of a tri lug that will be explained in the pistol portion.
Pistol- for the most part pistols are threaded to the host pistol via a piston which is a threaded portion placed inside of the silencer that can be changed to match different thread pitches found on different barrels. The system is commonly referred as a booster or Nielsen device. This allows a pistol with a browning style action (tilting barrel) to cycle when fired. Other attachment methods include direct thread options as well as a tri lug option. These are both very common with pistol caliber carbines or sub guns. The direct thread option works as expected; it has a threaded piece which threads into the rear of the silencer, which matches the thread pitch of a barrel. The tri lug option has two parts to its method. Without going in to great detail, there is an attachment device that is threaded to the muzzle with 3 locking lugs on it. Then a separate spring-loaded attachment device that goes into the back of the silencer slides over the locking lugs and with a twist it locks in place. It is a very efficient and very fast method for taking on and off a pistol silencer, and works well if you plan to move the can between hosts frequently or take it on and off regularly. It can be done with one hand, and even mounted under a rail is needed.
Rifle- rifle silencers come with a few different options for attachment; direct thread, and quick attach via a muzzle device. Some cans offer the ability to choose between the two as well. A direct thread silencer simply threads directly on to a threaded barrel. Some come in a specific thread pitch for certain rifles, and many even offer different threaded ends for the silencer to match the different thread pitches of different barrels. This allows for the use of the silencer on many more calibers and rifles.
Another very popular method is a QD system. This consists of a flash hider, muzzle break, or compensator that is threaded to the barrel to which the silencer will attach. This is a great option when a silencer may be moved from gun to gun while out shooting or at the very least taken on and off frequently and done so quickly. It simply allows ease of use. Choosing a QD system and how well you like it is important. Most companies offer some form of QD option and none of them seem to be compatible. So when you choose a QD option and buy all of the muzzle devices for your rifles you cannot down the road buy another brand and use it on the muzzle devices you currently have. There are a few exceptions however, in order to solve this problem, several companies have come out with the QD portions that work with their proprietary muzzle devices which you can then screw into the back of other silencer companies suppressors. It is great for the consumer, but something to be aware of before you purchase. While many NFA junkies do have many different brands with many different attachment methods, this is something to be aware of.
Other things to consider are if one handed on and off are a big deal to you, repeatability of the mount (discussed below), if you will be mounting the can under a rail etc.
Blowback- blowback is often referred to as back pressure. A silencer will increase the cyclic rate of a firearm because it increases the pressure above the levels without a suppressor. While this is not an issue on a single shot firearm like a bolt gun it does come in to play with semi and full auto fire. As the pressure increases the firearm will often cycle more quickly but beyond cyclic rate there are a few other issues that can be found due to the increased amount of gas. You will frequently hear the term over gassed or it said that something is gassy. This is usually when the silencer increases the amount of gas in system cycling the gun. This is part of what causes a gun to cycle harder or faster, but can lead itself to gassing the shooter. This takes place when shooting a suppressed firearm excess gas will “blowback” in ones face which can cause some burning to the eyes and make breathing unpleasant. While this is in many ways unavoidable to a certain extent many silencers cause lots of back pressure where others create little to none. Some of this can also have to do with the host firearm in use. Things like adjustable gas blocks, buffers weights and springs, bolt carrier groups, and other methods of tuning the gas system help to solve over gassing issues and for the firearm to run efficiently suppressed. Probably the largest issue with back pressure is that to much can cause what is called port pop. What this issue entails, is that while the silencer may be quiet at the muzzle you are getting lots of noise through the ejection port that is closer to the shooter and there for louder at the shooters ear. For this reason you will often hear people talk about decibels at the shooters ear rather than at the muzzle.
Point of impact shift/repeatability- adding a silencer can change the impact of projectiles from a firearm compared to when shooting it without one. While most of the time you will see groups tighten up with a silencer, where they impact with a set scope zero may be different with and without the silencer attached. This is commonly referred to as point of impact shift. It is most common and drastic in rifles, but can be seen in pistols as well, adjusting the can with the booster can help you to get projectiles landing where your sights are but for the most part it is never much of a worry. It also however, lends itself to being repeatable each time you use it to do the ability to adjust the can using the booster assembly this however is a minor detail. Where you see the most concern for point of impact shift is with rifles. A group may only move a half an inch to an inch in one direction or it may move 4” when taking the suppressor on or off, it just depends. Some silencers have less point of impact shift than others, but the thing most people concern themselves with is repeatability. Repeatability is when your rifle is zeroed with the silencer in place and the silencer is then later removed and replaced if the zero changes or if it is repeatable each time the silencer is reintroduced. This is undoubtedly the more important of the two. Just like some silencers have more or less point of impact shift than others this can often be made in to a larger deal than it is. However, some silencers are proven to be more repeatable than others, and this has a lot to do with design and attachment method.
Tone- tone is something you will hear people talk about that are often more seasoned NFA veterans or silencer users talk about. Tone is something many people may never think about while it is often the most important part to others. This is simply how a can sounds and is it pleasing to the ear. Often new comers care most about how quiet a can is and not much else. Tone is how a can sounds when a round is fired through it. It is high pitched or does it have a nice low thud to it. A low tone is what most people prefer, as a noise tends to be less perceived by the ear with a lower tone compared to a higher one. It just provides a more pleasant sound to the ear and shooting experience. Many will even say that a can with low tone may sound quieter than a can with a higher pitch even if a decibel meter disagrees.
Flash signature- flash signature may be another thing many may not consider and while it would have some obvious military applications it can apply to the average consumer as well. Silencers are great for use on a defensive weapon, a hunting rifle, and many other firearms. Often times they will be used at night. If you wish to use it in your home should the need arise, at night predator hunting, or while using night vision or other things out at night, flash suppression is something to consider. Barrel length and caliber comes largely in to play here but so does the length of the can you choose.
Longevity/durability- this is important for many reasons, first of all when you are spending your hard earned money on something, you want it to last. Especially something that is expensive, you have to wait for, and you can’t just run out and come home with a replacement in the same day. It comes in to play largely due to how much someone shoots through it (volume of fire), the rate of fire, is it being run hard and getting it super hot? Some people run them full auto, even on belt feds, you will see cans that are and are not full auto rated. Another thing that comes in to play is barrel lengths and just how rough it will be treated. While it is very hard to shoot out a can, it is possible. However, the better materials you have the longer it will last and suppress at its best.
Barrel length- many cans have a minimum barrel length on which they are suggested to be used and stay under warrantee. Others have no barrel length restrictions what so ever. You will see some companies that advertise baffles designed for SBR use and longevity among many other factors, but barrel length comes in to play when looking at longevity, and making the right choice for suppression needs. It is important to look at barrel length restrictions and assess what hosts the suppressor will be attached to for obvious reasons. It would not be fun to end up with a can that cannot be used on certain hosts and stay within the safe limits set by the manufacturer. Another very important thing to note is that as a general rule, the shorter the barrel the louder the boom. This means that a silencer will be less effective on a 10” SBR than it will be on a 16” rifle in the same caliber.
Reputation and service- some companies have great reputations in the industry for after market support, accessory availability, and superior customer service that will often go above and beyond. Others however, have poor reputations and customer service. It doesn’t take long to figure out which companies are which but it is something to strongly consider when making a purchase. Thanks to the NFA a silencer is not something a person can buy and then quickly get rid of if they are unhappy. A customer is investing not only a lot of money but also a lot of time into a company when choosing to buy their product. A company’s reputation comes from quality products; build materials, and performance along with customer service and support. Choosing a company that provides a confidence in their product and in the support you will receive after the fact is not to be overlooked. There are many stories to be found and heard that range from horror stories to the highest praises based on warranty work, fixing customer screw ups etc. It is wise to do some investigating or ask someone with more experience in the NFA world about a company before making a purchase.
Price- price is most certainly a factor but to a certain extent it is one of the last things to consider. With few exceptions most all quality silencers are competitively priced to one another. A consumer can run the spectrum from budget silencers all the way to the highest end options. Try to best assess the needs for a silencer to meet when striving for the best choice. Remember the investment that will be made is in both finances and time; it is not easily changed on a whim. While price is an important issue, it is worth noting that many consumers are unhappy with purchases made solely on a low price due to lack of performance or usability. However, this also goes the other way in understanding that spending the most money doesn’t always give a consumer the best performance, customer service, or ensure it is the can to best fit their needs.
Conclusion:
A person can suppress everything from a 22LR to a 50BMG and everything in between. There are even specialty silencers that include integrally suppressed firearms where the silencer is built as a part of the barrel and is a part of the firearm. Silencers specifically for shotguns, and AKs exist as well as many others. The chances are is that if you can shoot it, you can suppress it. Silencers serve most importantly to protect the hearing of the shooter as well as those around them. They increase accuracy; improve safety by allowing for ease of communication among other things. They reduce the noise signature not only for those close by but also for neighbors and others in the general distance. Silencers also make teaching others much more simple, and take away a lot of fear and anxiety from shooting firearms due to the reduction or removal of the large boom. Silencers are at home in all firearm situations from home defense, hunting, target shooting, and more. They simply provide a safer and more pleasurable experience for any and all firearm users.
This has hopefully served to further your knowledge of the NFA world and what it entails. Upon jumping in, it becomes much less confusing but it often takes a leap of faith. There are many more terms you will hear added to the fact many things have changed over the years so there is lots of new, old, and current information out there. Please feel free to ask any questions you have, and as many as you have. There is not a bad question to ask. NFA lovers know the market as well as the features of the products and can help guide you to making the best decision possible given what you wish to get from your purchase.
Joining the NFA (National Firearms Act) world: This means silencers, short-barreled rifles, shotguns, and even machine guns!
There is a lot of vernacular you will need to know when entering the NFA world in order to avoid confusion but you can also learn as you go like many others have. Some detail will be given here but nothing too deep.
Tax stamp- this is what you will receive back when the ATF has processed your paperwork and you can now take possession of your NFA item. It costs $200 and it is paid for when you submit your paperwork.
Jail- this is the time period you wait from the time that you file your paper work until it “gets out of jail” and you get to take it home.
Individual- a person may choose to have their NFA item transferred to a single individual this is beneficial as only that person is responsible for any paperwork
Trust- a NFA trust may be used by an individual to transfer a NFA item. When a NFA item is in a trust, all members of the trust have access of use to the NFA items it holds. This is beneficial for many reasons in the use of the items, as well as it allows for beneficiaries to be named in the event of death. The only draw back is all parties in the trust are responsible for some paperwork such as fingerprinting, photographs, and signatures.
Form 1- this is the form you file with the ATF to manufacture an NFA item. This can be used for silencers as well as short-barreled rifles and shotguns (not machine guns).
Form 4- this is the form that is filed with the ATF to transfer a NFA item to an individual, corporation, or trust.
Form 3- this form is used to transfer NFA items between dealers and distributors. You will commonly hear this if a dealer must order in a silencer for purchase, or on the new release of a new product.
SBR- Short Barreled Rifle. A rifle with a barrel less than 16” in length.
SBS- Short Barreled Shotgun. A shotgun with a barrel less than 18” in length.
Silencer- a device put on the muzzle of a firearm, to reduce the sound, and even flash signature of it. Also commonly referred to as suppressors, cans, and even mufflers. All terms are correct and are interchangeable.
Transferables- machine guns registered prior to May 19[SUP]th[/SUP] 1986 that are able to be owned by anyone however there are less than 200k and due to supply and demand their value continues to go up dramatically.
Post-Samples- Machine guns made after May 19[SUP]th[/SUP] 1986. They are for dealers, manufacturers, military, and police.
Sears- these are commonly called auto sears. There are a few different kinds, but they can be used with firearms such as an AR-15, or HK, which then gives the user a “fun switch” which is a term of endearment for full auto capabilities via the selector.
Short Barreled Rifles (SBRs) and Short Barreled Shotguns (SBSs)
You can buy a short-barreled rifle or shotgun directly from a dealer on a form 4. This is an option many choose so that they have a factory gun or because making the changes themselves is a hassle or not extremely practical which will now be discussed.
It is very common for people to obtain the firearm they wish to have as a SBR or SBS first in either pistol form, or with a 16” or longer barrel as a non-NFA item. When they have the firearm they will them submit a Form 1 to the ATF and await approval. This is also because the firearm is never in “jail” and it is in a person’s possession from day one. When the wait is over and the individual has received their tax stamp, they may then simply add a stock to the firearm if it is in pistol configuration, or have the barrel cut down to the desired length if the firearm was a non-NFA item originally due to barrel length.
Another important step in the form 1 process is that the item must be engraved with the manufacturer information. This would be the name of the individual or trust which filed the paper work, followed by the city and state of residence.
It is very common to form 1 a AR lower due to the fact at that point you can place any upper on it you wish with a barrel of less than 16” this is due to the fact it can always be converted back to it’s original length.
Silencers
Silencers can be manufactured on a form 1, but it is most common to purchase them from a dealer on a form 4. This is where you will most commonly hear people talk about things in jail. When you purchase a silencer from a dealer the dealer should then help you submit the form 4 and in many cases take care of most of it for you. It is at this point you will wait for approval. Upon the return of your tax stamp to the dealer, the customer is contacted and may come pick up their item upon completion of a 4473 (NICS background check).
Which Silencer is right for you??
The big question is what do you want out of the silencer? Many want the quietest silencer they can get, others want something that is light weight, the most durable, something that suppresses the most calibers possible, and the list goes on. Hearing safe levels are said to be anything that is 140 decibels or under. Many things come in to effect when suppressing a firearm and the level of suppression one will get which will be discussed.
There are many features the consumer must consider and perhaps rank in order of importance so they may choose the can that best serves their needs. It is not possible to have it all.
Suppression- amount of decibels the silencer reduces the sound signature. Most all silencers on the market are hearing safe with exceptions made when very short silencers began to be used on short barrels or very large calibers. However, some silencers are quieter than others. There are a few trade offs for better suppression but the largest is a longer length.
Subsonic and supersonic- subsonic and supersonic have to do with the speed of sound. Something traveling slower than the speed of sounds is subsonic where as something traveling faster than the speed of sound is supersonic. With suppressors this pertains to bullet speeds and sound. When something is traveling faster than the speed of sound a sonic boom takes place. For this reason when some rifle and pistol rounds leave a barrel a sonic boom occurs. The speed of sound changes based on your elevation but it generally ranges from 1,100ish feet per second on down as elevation increases. When a sonic boom occurs it puts a large crack out in to the air. This is not the gun making the noise or the silencer failing to suppress the gunshot but rather the projectile traveling through the atmosphere creating the noise. This is important because depending on what guns are being shot and the ammunition going through them the amount of noise made will vary.
Silencer length- the length of a silencer is very important as it plays in to so many other factors. Silencer length affects the following things. Number one is the sound suppression, as the longer a silencer is generally the more decibel reduction it will yield. The overall length of the firearm a silencer is attached to sometimes make it more or less maneuverable. Weight is something to also consider, the more material you have the more it will weigh. Flash signature is a factor at which some may scoff or not give thought to, but the longer a silencer is the better it will reduce or even hide the flash signature or a firearm. Back pressure is also affected by silencer length, the longer a silencer is, the more it tends to increase the backpressure (read more below). And tone, many times short or long versions of the same suppressor will sound very different from one another. There is a modular trend however that is very popular in pistol cans, and can be found on some rifle cans as well. This is where the silencer essentially has two parts. There is a front module that can be added or removed to change the length thus affecting all of the attributes listed above; most importantly the overall length, weight, and amount of suppression. Short silencers will often be referred to as K cans. These cans are made to be shorter and lighter than what is usually a full sized version of it. While some suppressor users are very concerned with performance, others are more concerned weight, length and other listed variables as long as they are hearing safe. But one needs to consider barrel lengths (rifles) and other variables when making the right choice for them. There are many reasons to have both full sized as well as K cans.
Weight- the weight of a silencer can be very important for many reasons, you are hanging it off the end of your gun, and often carrying it around, holding it up to shoot etc. This varies in importance from person to person and with intended use. The build materials and size of the can are what most influences weight.
Build materials- Silencers are constructed from a wide range of materials. With few exceptions, there are two basic parts of a silencer, the outer tube, and the baffles stack or monolithic core inside of it. Some silencers feature individual baffles stacked together, and others feature a monolithic core where the entire system is one piece. However, the metal from which they are constructed is what really matters.
-Aluminum is common due to its lightweight nature, you will see it in 22 cans and with a few exceptions elsewhere.
-Chrome Moly Steel is a low-cost alternative that is ok for a lower volume of fire on longer barrels
-Stainless Steel is probably the most popular material used for baffles of which there are many grade that won’t be delved into. Stainless is durable, corrosion resistant, it’s not extremely expensive, and it holds up well to heat as well as hard chemicals. It is much easier to clean than aluminum if the can is serviceable.
-Titanium is lightweight and durable; it is often used where weight and precision are important. Unfortunately however, it is fairly expensive so silencers that feature titanium baffles tend to command a higher price. It isn’t uncommon to find complete titanium silencers, as well as silencers that have blast baffles (the first baffle in the silencer) that takes the brunt of the abuse that is a more durable material (see Inconel and Stellite). Then followed by all titanium baffles to make it as light as possible (this is sometimes seen with stainless steel as well).
-Inconel is a durable alloy that can handle extreme abuse and heat while not being terribly heavy. It is hard to work with but used to be the standard in durability, it can still be found but many companies have moved on from it
-Stellite is much more expensive than stainless steel but vastly superior to Inconel under the hardest use and conditions. Stellite has unparalleled hardness and toughness with a very high melting point, it also excels over other baffle materials in wear and erosion resistance. It is a great choice for short barrels and high schedule of fire, or any other abuse that someone may throw at it.
User serviceable- this is mainly important for rimfire cans as 22lr and other rimfire ammunition can be very dirty and it necessary for them to be cleaned from time to time. If a person wishes to shoot lead or cast pistol bullets it is also necessary to have a pistol can that is serviceable but in general it is not needed. Rifle cans for the most part are not serviceable and do not require any service.
Multi-caliber- many silencers on the market feature the ability to span a wide range of calibers. There are some that target this niche specifically. It is important to understand that one should always check with a manufacturer if they are unsure about a caliber and shooting it through their suppressor before doing so. Due to build materials, barrel length, and pressures of different calibers, certain cans may or may not be rated for a firearm you have.
With that said, as a general rule if it will fit through the hole it’s possible, but if the bullet is larger than the diameter of the silencer, you will simply destroy your expensive muzzle device.
What this means is that a shooter can shoot 223/5.56 through a .30caliber silencer without any issues, however the inverse would not be true. This is beneficial in part because a purchase of a .30caliber silencer can be made and cover all rifles from 223 all the way to 300winmag. This benefits the consumer because there is not any loss in performance shooting 223 through a 30caliber can over a caliber specific 223 can to speak of and some benefits such as lower back pressure are achieved. The same is true for pistols. Shooting 9mm through a 45caliber silencer suppresses just as well as a 9mm caliber specific can and then the shooter isn’t required to buy a silencer for every caliber they intend to shoot. Silencers in 30caliber, 45ACP, and 22LR will very effectively meet all needs.
Some companies have attempted to meet market demands for modularity by offering silencer than can be shot on pistols and rifles both. For example a silencer can be purchased to shoot 9mm, 22LR (serviceable) and all rifle calibers up to 300winmag, as the can has a diameter of .357 (9mm). Another example offering on the market offers the ability to shoot firearms ranging from from 9mm to 45ACP on pistols and 5.56 to 45-70 on rifles and everything in between (covering all 30caliber options). The only issue to consider with these cans is that they tend to make some compromises to achieve such a wide range of use and application. Many times the cans that are well designed for pistols do not perform as well on rifles. They also do not possess the ability to hold up to the schedule of fire can multi-caliber can would that was best designed for rifles. On the other side of that issue, a multi-caliber silencer that is well suited for rifles may be very heavy, bulky, and unwieldy hanging on the end of a pistol. They are however a great option for those certain they will not purchase multiple silencers.
Method of attachment-
Rimfire-most all rimfire cans are direct thread, however some QD (quick detach) options do exist mainly in the form of a tri lug that will be explained in the pistol portion.
Pistol- for the most part pistols are threaded to the host pistol via a piston which is a threaded portion placed inside of the silencer that can be changed to match different thread pitches found on different barrels. The system is commonly referred as a booster or Nielsen device. This allows a pistol with a browning style action (tilting barrel) to cycle when fired. Other attachment methods include direct thread options as well as a tri lug option. These are both very common with pistol caliber carbines or sub guns. The direct thread option works as expected; it has a threaded piece which threads into the rear of the silencer, which matches the thread pitch of a barrel. The tri lug option has two parts to its method. Without going in to great detail, there is an attachment device that is threaded to the muzzle with 3 locking lugs on it. Then a separate spring-loaded attachment device that goes into the back of the silencer slides over the locking lugs and with a twist it locks in place. It is a very efficient and very fast method for taking on and off a pistol silencer, and works well if you plan to move the can between hosts frequently or take it on and off regularly. It can be done with one hand, and even mounted under a rail is needed.
Rifle- rifle silencers come with a few different options for attachment; direct thread, and quick attach via a muzzle device. Some cans offer the ability to choose between the two as well. A direct thread silencer simply threads directly on to a threaded barrel. Some come in a specific thread pitch for certain rifles, and many even offer different threaded ends for the silencer to match the different thread pitches of different barrels. This allows for the use of the silencer on many more calibers and rifles.
Another very popular method is a QD system. This consists of a flash hider, muzzle break, or compensator that is threaded to the barrel to which the silencer will attach. This is a great option when a silencer may be moved from gun to gun while out shooting or at the very least taken on and off frequently and done so quickly. It simply allows ease of use. Choosing a QD system and how well you like it is important. Most companies offer some form of QD option and none of them seem to be compatible. So when you choose a QD option and buy all of the muzzle devices for your rifles you cannot down the road buy another brand and use it on the muzzle devices you currently have. There are a few exceptions however, in order to solve this problem, several companies have come out with the QD portions that work with their proprietary muzzle devices which you can then screw into the back of other silencer companies suppressors. It is great for the consumer, but something to be aware of before you purchase. While many NFA junkies do have many different brands with many different attachment methods, this is something to be aware of.
Other things to consider are if one handed on and off are a big deal to you, repeatability of the mount (discussed below), if you will be mounting the can under a rail etc.
Blowback- blowback is often referred to as back pressure. A silencer will increase the cyclic rate of a firearm because it increases the pressure above the levels without a suppressor. While this is not an issue on a single shot firearm like a bolt gun it does come in to play with semi and full auto fire. As the pressure increases the firearm will often cycle more quickly but beyond cyclic rate there are a few other issues that can be found due to the increased amount of gas. You will frequently hear the term over gassed or it said that something is gassy. This is usually when the silencer increases the amount of gas in system cycling the gun. This is part of what causes a gun to cycle harder or faster, but can lead itself to gassing the shooter. This takes place when shooting a suppressed firearm excess gas will “blowback” in ones face which can cause some burning to the eyes and make breathing unpleasant. While this is in many ways unavoidable to a certain extent many silencers cause lots of back pressure where others create little to none. Some of this can also have to do with the host firearm in use. Things like adjustable gas blocks, buffers weights and springs, bolt carrier groups, and other methods of tuning the gas system help to solve over gassing issues and for the firearm to run efficiently suppressed. Probably the largest issue with back pressure is that to much can cause what is called port pop. What this issue entails, is that while the silencer may be quiet at the muzzle you are getting lots of noise through the ejection port that is closer to the shooter and there for louder at the shooters ear. For this reason you will often hear people talk about decibels at the shooters ear rather than at the muzzle.
Point of impact shift/repeatability- adding a silencer can change the impact of projectiles from a firearm compared to when shooting it without one. While most of the time you will see groups tighten up with a silencer, where they impact with a set scope zero may be different with and without the silencer attached. This is commonly referred to as point of impact shift. It is most common and drastic in rifles, but can be seen in pistols as well, adjusting the can with the booster can help you to get projectiles landing where your sights are but for the most part it is never much of a worry. It also however, lends itself to being repeatable each time you use it to do the ability to adjust the can using the booster assembly this however is a minor detail. Where you see the most concern for point of impact shift is with rifles. A group may only move a half an inch to an inch in one direction or it may move 4” when taking the suppressor on or off, it just depends. Some silencers have less point of impact shift than others, but the thing most people concern themselves with is repeatability. Repeatability is when your rifle is zeroed with the silencer in place and the silencer is then later removed and replaced if the zero changes or if it is repeatable each time the silencer is reintroduced. This is undoubtedly the more important of the two. Just like some silencers have more or less point of impact shift than others this can often be made in to a larger deal than it is. However, some silencers are proven to be more repeatable than others, and this has a lot to do with design and attachment method.
Tone- tone is something you will hear people talk about that are often more seasoned NFA veterans or silencer users talk about. Tone is something many people may never think about while it is often the most important part to others. This is simply how a can sounds and is it pleasing to the ear. Often new comers care most about how quiet a can is and not much else. Tone is how a can sounds when a round is fired through it. It is high pitched or does it have a nice low thud to it. A low tone is what most people prefer, as a noise tends to be less perceived by the ear with a lower tone compared to a higher one. It just provides a more pleasant sound to the ear and shooting experience. Many will even say that a can with low tone may sound quieter than a can with a higher pitch even if a decibel meter disagrees.
Flash signature- flash signature may be another thing many may not consider and while it would have some obvious military applications it can apply to the average consumer as well. Silencers are great for use on a defensive weapon, a hunting rifle, and many other firearms. Often times they will be used at night. If you wish to use it in your home should the need arise, at night predator hunting, or while using night vision or other things out at night, flash suppression is something to consider. Barrel length and caliber comes largely in to play here but so does the length of the can you choose.
Longevity/durability- this is important for many reasons, first of all when you are spending your hard earned money on something, you want it to last. Especially something that is expensive, you have to wait for, and you can’t just run out and come home with a replacement in the same day. It comes in to play largely due to how much someone shoots through it (volume of fire), the rate of fire, is it being run hard and getting it super hot? Some people run them full auto, even on belt feds, you will see cans that are and are not full auto rated. Another thing that comes in to play is barrel lengths and just how rough it will be treated. While it is very hard to shoot out a can, it is possible. However, the better materials you have the longer it will last and suppress at its best.
Barrel length- many cans have a minimum barrel length on which they are suggested to be used and stay under warrantee. Others have no barrel length restrictions what so ever. You will see some companies that advertise baffles designed for SBR use and longevity among many other factors, but barrel length comes in to play when looking at longevity, and making the right choice for suppression needs. It is important to look at barrel length restrictions and assess what hosts the suppressor will be attached to for obvious reasons. It would not be fun to end up with a can that cannot be used on certain hosts and stay within the safe limits set by the manufacturer. Another very important thing to note is that as a general rule, the shorter the barrel the louder the boom. This means that a silencer will be less effective on a 10” SBR than it will be on a 16” rifle in the same caliber.
Reputation and service- some companies have great reputations in the industry for after market support, accessory availability, and superior customer service that will often go above and beyond. Others however, have poor reputations and customer service. It doesn’t take long to figure out which companies are which but it is something to strongly consider when making a purchase. Thanks to the NFA a silencer is not something a person can buy and then quickly get rid of if they are unhappy. A customer is investing not only a lot of money but also a lot of time into a company when choosing to buy their product. A company’s reputation comes from quality products; build materials, and performance along with customer service and support. Choosing a company that provides a confidence in their product and in the support you will receive after the fact is not to be overlooked. There are many stories to be found and heard that range from horror stories to the highest praises based on warranty work, fixing customer screw ups etc. It is wise to do some investigating or ask someone with more experience in the NFA world about a company before making a purchase.
Price- price is most certainly a factor but to a certain extent it is one of the last things to consider. With few exceptions most all quality silencers are competitively priced to one another. A consumer can run the spectrum from budget silencers all the way to the highest end options. Try to best assess the needs for a silencer to meet when striving for the best choice. Remember the investment that will be made is in both finances and time; it is not easily changed on a whim. While price is an important issue, it is worth noting that many consumers are unhappy with purchases made solely on a low price due to lack of performance or usability. However, this also goes the other way in understanding that spending the most money doesn’t always give a consumer the best performance, customer service, or ensure it is the can to best fit their needs.
Conclusion:
A person can suppress everything from a 22LR to a 50BMG and everything in between. There are even specialty silencers that include integrally suppressed firearms where the silencer is built as a part of the barrel and is a part of the firearm. Silencers specifically for shotguns, and AKs exist as well as many others. The chances are is that if you can shoot it, you can suppress it. Silencers serve most importantly to protect the hearing of the shooter as well as those around them. They increase accuracy; improve safety by allowing for ease of communication among other things. They reduce the noise signature not only for those close by but also for neighbors and others in the general distance. Silencers also make teaching others much more simple, and take away a lot of fear and anxiety from shooting firearms due to the reduction or removal of the large boom. Silencers are at home in all firearm situations from home defense, hunting, target shooting, and more. They simply provide a safer and more pleasurable experience for any and all firearm users.
This has hopefully served to further your knowledge of the NFA world and what it entails. Upon jumping in, it becomes much less confusing but it often takes a leap of faith. There are many more terms you will hear added to the fact many things have changed over the years so there is lots of new, old, and current information out there. Please feel free to ask any questions you have, and as many as you have. There is not a bad question to ask. NFA lovers know the market as well as the features of the products and can help guide you to making the best decision possible given what you wish to get from your purchase.
