Guns Daniel Defense ISR in 300 BLK Recoil Staff May 23, 2013 0 COMMENT Still wondering about the Daniel Defense ISR (Internally Suppressed Rifle) we mentioned back in February? Engineered from the ground up to shoot the 300BLK round, it combines the short barrel of an SBR with an integral suppressor so you only need one tax stamp to own (as opposed to one each for the short barrel and suppressor on other weapons). Jay Duncan explains the advantages in this interview from Personal Defense Network. http://youtu.be/UeZE5tNkbOA Though it features a 10.3″ barrel, the lsound suppressor is threaded and welded to the ISR’s unique integrated gas block, making the overall barrel length is just 16.145″. This leaves only the suppressor requiring the NFA stamp. More information at Daniel Defense.