SJC SBR Compensators

Installation Instructions

Contact S & J Customs first if you do not understand and accept the following instructions:

  1. It is your responsibility to make sure your pistol or rifle is unloaded and safe before starting.

  2. Please verify that the compensator provided has the same thread diameter and pitch as the threads on your barrel. Since different caliber compensators may use the same thread diameter and pitch, it is also important to verify you are installing a compensator with adequate bore clearance for your caliber.  Measure the bore of the provided compensator and the diameter of your bullets, or simply pass one of your bullets through the entire bore of the compensator before installing.

  3. Please note that the bore diameter of SJC compensators is purposefully tight to assure maximum usage of available gasses.  Therefore it is imperative that the barrel threading is aligned with the bore axis.  Poorly aligned threads could allow for possibly dangerous baffle strikes when the bullet is fired through the compensator.

  4. SJC SBR Compensators are intended to install after verifying all dimensions with peel, crush washer, or machining the comp shoulder to allow indexing the compensator to your preference.

  5. It is important to note that the properly installed comp body is only safe to shoot with the insert bushing removed or completely threaded into the comp body until the flange is flush. There should be no in between. Thread locking products may be used to assist in making sure the insert bushing does not loosen, but were not used during our testing. Verification of the insert bushing being properly installed from shot to shot is and must remain the responsibility of the shooter.

  6. After installation of the compensator and one of the two insert bushings on your firearm according to the directions above, hold the firearm as neutral as possible and shoot a rapid string of the chosen load. If the shot string indicates excess downward thrust from shot to shot then the thrust may be lessened by opening up the bore diameter of the insert bushing a few thousandths of an inch.

  7. This enlarging process can be accomplished with a hand drill, drill press, or lathe using right hand twist bits of slightly increasing diameters. The compensator body makes a suitable jig to hold the bushing for drilling but should not be used until it’s been safely removed from the firearm!  Drill only through the bore of the bushing. Do not drill the comp body.
  8. Repeat steps 7 and 8 until shot strings indicate insufficient downward thrust.  Then, drill the previously unused bushing to the last best diameter for your given load.