Everything You Need to Know about Suppressors and Barrel Lengths

Suppressors are a popular option for reducing the sound or “report” of your firearm. In this article we are going to be covering suppressors and their effect on barrel length specifically.

You may already be aware that you need a tax stamp from the ATF for a suppressor as well as a tax stamp if you possess a short barrel rifle. (One with a barrel length of less than 16 inches.) Each of these tax stamps cost $200 and must be purchased separately.

Originally and still for some these “tax stamp” fees really added to the cost of your firearm. If you are looking for ways to save some of that cost you might be wondering, Does a suppressor count as barrel length?

While a suppressor and barrel are two separate parts of a firearm, a permanently attached suppressor does add both to the length of the barrel and the overall length of the weapon itself. This means that by having your suppressor welded on it does increase your barrel length and can reduce the need for a SBR tax stamp.

Why Does the Length of My AR Barrel Matter?

If the overall length of a rifle is less than 25 inches, or the barrel is less than 16 inches in length then the weapon is classified as a short barreled rifle by the ATF. This comes with a $200 tax stamp requirement and a whole host of rules on where you can take it, store it. You also need to obtain permission to cross state lines with said rifle. 

You can find a link to the ATF’s resource on suppressors and other firearm related details here.

So while it is somewhat popular to have more compact rifles that would fall into the SBR requirement, many people do not want to pay this fee nor deal with the associated restrictions.

Some have found that by adding a device which affixes to the end of the barrel they can avoid these restrictions. Devices that can attach to the end of the muzzle include flash suppressors, muzzle brakes and sound suppressors or silencers as they are sometimes called.

A Suppressor and Using It to Extend the Length of Your Barrel

There are numerous ways that a suppressor can be attached to your rifle and these include a threaded screw on method and a quick disconnect method that may rely on a secondary part which is attached to your barrel. 

While both these and other types of suppressors can visually extend the length of your barrel, unfortunately in these removable configurations the ATF does not count them as barrel length.

The one caveat to using a suppressor to extend the length of your barrel is the requirement for it to be pinned and welded in place. 

“The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over.

This would mean that in order to avoid a SBR tax stamp on an AR with a 12 inch barrel you would need a 4 inch suppressor that was permanently attached to the rifle and welded in place. 

However, in this instance you are still paying for a tax stamp for the suppressor, and have still locked all of the required restrictions onto that particular rifle since the suppressor is now welded to it. You may have just paid for the SBR tax stamp so that you could use the suppressor on your longer guns as well in this instance.

The Ideal Solution to Extending Your Barrel Length Using a Suppressor

Some of the quick connect style suppressors can be paired with a muzzle brake. In these cases the muzzle brake is attached to the barrel and the suppressor is then slid over that attaches to it.

By using one of these you can permanently attach the muzzle brake/adapter to your rifle and then remove the suppressor to avoid the restrictions that accompany the suppressor use.  

So for instance you can attach a 2.6 inch Surefire Muzzle Brake/Adapter to a 14 inch barrel bringing the total length to over 16 inches. Pin and weld this in place and it is no longer a short barreled weapon. 

You can then attach your suppressor to the adapter and use it as you like. However, remember the suppressor and any weapon it is actively attached to have the restrictions. But you could always remove the suppressor and store it in your safe. Then you can carry your weapon in accordance with normal laws. 

The surefire muzzle brake I use can be found on Optics Planet. I purchased three of these 1 for each of my weapons, and then I simply attached the suppressor to whichever rifle I want to use it on. (1 AR pistol, 1 SBR and 1 20 inch barrel for distance shooting.)

The suppressor I have is the Socom SB2, I was able to find a local dealer to pick it up. This was far easier than ordering it off line and getting it sent to an FFL licensed location.

Make sure to purchase a muzzle brake and suppressor appropriate for your caliber rifle.

Conclusion – Can a Suppressor Be used to Extend Legal Barrel Length

In short, yes a suppressor can be used to legally extend the barrel length of your rifle if properly attached. However, opting for a quick attach suppressor and a permanently attached muzzle brake is likely a better option if you are trying to avoid the need for an SBR tax stamp. 

As you can see there are several nuances to the laws governing suppressors and rifles, with that in mind remember to always check your state’s laws as well as any updates from the AFT as they often change or modify their rulings on specific subjects.