Received from RPB USA an AK-74 compensator/brake and an adapter. Both pieces came parkerized, and look well made and finished.
Have questions about the adapter.
The inner bore is plain- no threads- to install over the plain turned down barrel.
One end of the adapter is threaded externally and the face on the same end has four deep notches spaced evenly, and two shallow notches 180 degrees opposite.
The other end is unthreded and has two external wrench flats(?).
Does the unthreaded/wrench flat end go into the muzzle brake, and the notch side against the forward side of the front sight base?
Originally, was there a pin that locked the brake to the FSB?
Am planning on permanently attaching the muzzle brake/compensator to the adapter, with the shallow notches pointing upper and lower, then attach the assembly to the barrel and/or FSB somehow. Thinking of a drilling and pinning crossways along the bottom of the barrel.