Is the OAL of an SBR Measured with the Stock Fully Extended or Collapsed?

In a previous blog article we discuss the process to measure the overall length (OAL) of your SBR for the ATF Form 1.  However, we still frequently get asked what the OAL of your SBR actually means.  When you are measuring the OAL of your SBR, for your ATF Form 1 or your ATF Form 4 you will need to measure the total length of your SBR with the stock fully extended.  If you have any removable muzzle devices you will need to remove them, when measuring your SBR.  Since the muzzle device is removable, the muzzle devices are not considered to be a part of the OAL of your SBR.