Short Barreled Rifles and Multiple Configurations

If you own a SBR based on the AR platform chances are you have, or are tempted to buy, multiple uppers for the firearm. This is just fine if you follow a few technicalities.

First: The Firearm

A short barreled rifle (SBR) is defined as a rifle with a barrel less than 16” in length. When such rifle is made, the ATF records the maker, model, barrel length, caliber, and overall length of the firearm.

For the AR platform, the firearm is the lower receiver. This means you can physically change the upper, thereby changing the barrel length, caliber, and overall length, without making a new NFA firearm.

But the Paper Says . . .

However, you’ll notice that your Form 4 (or Form 1) has the SBR registered with a particular barrel length, caliber, and overall length. When you change the upper, you change these measurements.

It is ok to change these, but you must notify the ATF of the changes. This requirement is found on the Form 1 and Form 4 under the “Change of Description” heading in the Important Information for Currently Registered Firearms section.

Notification Procedure

So you are making a change and need to notify the ATF. What to do?
Put together a letter.
You’ll be sending it to the ATF at:

NFA Division Bureau of Alcohol, Tobacco, Firearms and Explosives
244 Needy Road
Martinsburg, WV 25405

Next, draw their attention to the firearm in question:

The XXX NFA Revocable Trust is the owner of registered SBR 123456 manufactured by GunMaker Inc.

Now, assuming this is an additional configuration and not a replacement, provide the information regarding the additional configurations.

In addition to the current configuration(s) of SBR 123456, the firearm may also be found in the following configurations:

Barrel Length Overall Length Caliber
10″ 22″ 5.56 mm
8.5″ 20.5″ .300

Last, provide a request for amending the record and a kind closing:

Please amend the registry entry for this firearm with the provided additional configurations. If you have any questions, do not hesitate to contact me at [phone number] or [email].

XXX, Trustee

With the letter

Once you have your drafted letter, create two copies. One is for your records; the other will be sent to the ATF. To make your request clearer, include a copy of the Form 1 or Form 4 with the letter. This way the ATF knows exactly which firearm you intend to change.

Record Keeping

The ATF does not always respond, hence the need to save a copy of the letter. However, once you have notified the ATF, you have satisfied the requirement on the Form 4 or Form 1.

Changes you can’t make

It is worth noting that there are some changes you cannot make. You cannot change firearm type. If you have a SBR, you cannot change to a shotgun barrel and make a SBS. You also cannot change either the SBS or SBR to a Destructive Device. Thus you must remain within the class of firearm that is registered.

Notifying the ATF about additional configurations is quite easy. Sometimes the hardest part is getting around to it. If I can ever be of assistance with this, or another matter, please do not hesitate to reach out.