AR15/M4 Super Reaction Rod The Super Reaction Rod was designed with the advanced armorer in mind, an armorer who frequently works on AR15/M4 platforms with over torqued, seized or Loctited barrel nuts. The Super Reaction Rod works by pre-loading the barrel nut extension to the lugs of the Super Reaction Rod to eliminate any movement before adding torque to the barrel nut, while at the same time fixing the upper receiver into place. Having the barrel nut extension mated to the Super Reaction Rod lugs and fixing the upper receiver before torquing will remove any potential stress that could be placed on the index pin. This allows the armorer to place tremendous torque on the barrel nut. The Super Reaction Rods pre-loading system can also be removed to allow it to work just like a standard Reaction Rod, which allows upper work to be performed in a 360° both vertically, and horizontally.