It is my understanding that in order for a bullpup rifle NOT to be classified as an SBR the barrel
itself must be over 16.0" in length, and that the over all length of the rifle must be over 26.0".

My questions:

Does the official OAL measurement  include whatever flash hider, comp or brake that is attached to the 16.0+" barrel?

Also, if the barrel is over 16.0", can the chosen muzzle device be removable?

Thank you!

Overall length measurements only include the flash hider if it is permanently attached to the barrel via pin, welded, silver solder, ect. If it's removeable, it's not counted.

On a Tavor the actual barrel length is 16.5".  The flash hider cn be removed by loosening the lock nut.  Supposedly the ATF uses a rod in the barrel to measure barrel length from a closed bolt.   If the barrel is less than 16" you have to have a permanently attached FH or brake to make it greater thn16".  

An example if you have a 14.5" AR-15 barrel and permanently attached longer FH to make the overall length greater than 16" your legl.   If the barrel is shorter than 16" you need a Short Barrel rifle permit/stamp under NFA rules if the weapon meets the definition of a rifle.

Great responses, thank you both.

I am getting mixed messages about determining the official OAL with & without a muzzle device.
In this case, naked barrel length is good, but the OAL is in question.

Here is the scenario:

16.25" M1A barrel without  the gas lock and gas plug renders an OAL of about 24.5", but the rifle is not functional.

Adding the gas lock and gas plug makes the rifle functional, but the OAL is 25.5" in a Rogue bullpup conversion kit.


Possible solutions:

1. Add a spacer to the rear and increase the OAL.
... JTactical has a heavy 2" butt stock spacer, but fabricating a custom light weight spacer shouldn't be that difficult.

2. Silver solder the muzzle device pictured below in place, so that it can not be removed.

3. ???  your thoughts.


The OAL as pictured below is 27.75"

I happen to know a guy with mad welding skills, thanks.

UPDATE:

With regards to M14/M1A bullpup conversions meeting the NFA overall length (OAL) requirement of 26.0"

The official measurement is taken from the end of the butt stock to the crown of the barrel.
The 16.25" SOCOM barrel renders an OAL of 24.50".

Unless you want to add the 14.0 ounce, 2.0" factory butt stock spacer,
the 16.25" barrel does NOT meet NFA OAL requirements in the Rogue.


Bottom line:

Choosing an M14/M1A with an 18 or 22 inch barrel is the very BEST choice for your bullpup conversion.
An 18.0" barreled action in the Rogue renders a legal OAL of 26.25" when measured butt stock to crown.

Pin & Weld is not a viable option on the 16.25" barrel.

What about silver soldering on the 16.25? That way you aren't hurting the threads or harming the rifle in any way

Silver solder was discussed and quickly dismissed.
Also, I believe pin & weld is the only method approved by the NFA.


The rifle is disassembled and in storage.



EDIT: The butt stock extension is an easy fix, however, it adds fourteen (14) ounces to kit that is already
heavy, and it increases the already long length of pull from fifteen (15) inches to seventeen (17) inches.

Constructive Intent?
Really IDK.

Admittedly, the chances of some agent actually checking the OAL is slim, but I prefer to be in full compliance and not risk it.

The situation resolved itself this morning ... I sold the JTactical conversion kit.

http://www.atf.gov/files/publications/download/p/atf-p-5320-8/atf-p-5320-8-chapter-2.pdf